Hot water supply heater

Abstract

To suppress shortage of the number of connection terminals of a control device that controls a hot water supply heater.SOLUTION: A hot water supply heater 1 includes a control device 70A and a switching circuit 91 capable of switching a heating remote controller 73 that becomes in a communication state. The switching circuit 91 includes: a plurality of control device side connection parts A1-A4, B1-B3 having a plurality of first ports A1-A4 and a plurality of second ports B1-B3; first transistors TR1A-TR10A; and second transistors TR1B-TR10B. The switching circuit is configured so that remote controller side connection parts D1-D10 to be communicably connected to input / output terminals T8, T9 out of the plurality of remote controller side connection parts D1-D10 are switched in accordance with a combination of a high-level signal and a low-level signal of a switching signal in the plurality of first ports A1-A4 connected to emitters E of the respective second transistors TR1B-TR10B and the plurality of second ports B1-B3 connected to bases B of the respective second transistors TR1B-TR10B.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a water heater and heater.

Background Art

[0002] Patent Document 1 describes a hot water supply device. This hot water supply device includes a heat source machine having a controller and a connection terminal unit. The connection terminal unit has a plurality of connection terminals. The plurality of connection terminals are arranged adjacent to each other in a row, and each connection terminal is connected to a communication cable of a bathroom heater or a plurality of different floor heaters. The controller controls the overall operation of the heat source machine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a controller for controlling the overall operation of a hot water control device or the like, a control device such as a microcomputer is generally used. Since the hot water supply device of Patent Document 1 needs to connect each connection terminal to a communication cable according to the number of external heating terminals such as a bathroom heater and a plurality of different floor heaters, a control device connection terminal corresponding to the maximum number of connectable external heating terminals is required. When applying the configuration of Patent Document 1 to a water heater and heater with a large number of external heating terminals, a shortage of the number of connection terminals of the control device is assumed. In this case, there is a problem that it is necessary to use a control device with a large number of connection terminals or increase the number of control devices, resulting in an increase in manufacturing cost.

[0005] One object of the present disclosure is to suppress a shortage of the number of connection terminals of a control device for controlling a water heater and heater.

Means for Solving the Problems

[0006] One of the present disclosures, a hot water heater, is configured to supply the heat medium to a plurality of heat radiation terminals having a terminal flow path through which the heat medium flows, and controls a switching valve that switches between a first state that permits the supply of the heat medium to the terminal flow path and a second state that shuts off the supply, a hot water supply circuit that heats water supplied from the outside and supplies hot water, a burner that burns gas, a heat exchanger that is heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path, and is configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger, and a control board communicably connected to a plurality of remote controls corresponding to the plurality of heat radiation terminals. The control board includes a control device having a plurality of connection terminals and a switching circuit capable of switching the remote control in a communication state with the control device. The switching circuit includes a remote control side connection portion electrically connected to each of the remote controls, a control device side connection portion electrically connected to each of the connection terminals, a first transistor having a first control terminal and a pair of first main terminals, and a second transistor having a second control terminal and a pair of second main terminals. The plurality of control device side connection portions have a plurality of first ports and a plurality of second ports. The plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports. One of the pair of first main terminals in the first transistor is electrically connected to the remote control side connection portion, and the other is electrically connected to the input / output terminal. One of the pair of second main terminals in the second transistor is electrically connected to the first control terminal, the other is electrically connected to one of the first ports, and the second control terminal is electrically connected to one of the second ports. Depending on the combination of the switching signals applied to each of the first ports and each of the second ports, the remote control side connection part that is communicably connected to the input / output terminal is selected from among the plurality of remote control side connection parts and switched.

[0007] A hot water heater which is one of the present disclosures is configured to be able to supply the heat medium to a plurality of heat dissipation terminals having a terminal flow path through which the heat medium flows, and controls a switching valve that switches between a first state that permits the supply of the heat medium to the terminal flow path and a second state that shuts off the supply, a hot water supply circuit that heats water supplied from the outside to supply hot water, a burner that burns gas, a heat exchanger that is heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path, and a heating circuit configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger, a control board connected to a plurality of remote controls corresponding to the plurality of heat dissipation terminals via communication means, and includes the control board includes a control device having a plurality of connection terminals and a switching circuit capable of switching the remote control in a communication state with the control device, the switching circuit includes each remote control side connection part electrically connected to each remote control, each control device side connection part electrically connected to each connection terminal, and a plurality of transistors, the plurality of control device side connection parts have a plurality of first ports and a plurality of second ports, the plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports, the sum of the number of the plurality of first ports and the number of the plurality of second ports is less than the number of the plurality of remote control side connection parts, The switching circuit switches to select, according to the combination of the switching signals applied to each of the first ports and each of the second ports, the remote control side connection part that is communicably connected to the input / output terminal from among the plurality of remote control side connection parts.

Effect of the Invention

[0008] According to the technology related to the present disclosure, it is possible to suppress a shortage in the number of connection terminals of a control device that controls a water heater and a heater.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Each of the following [1] to [4] is an example of a water heater and a heater included in the present disclosure.

[0011] 〔1〕 A water heater and a heater configured to be able to supply a heat medium to a plurality of heat radiation terminals having a terminal flow path through which the heat medium flows, and controlling a switching valve that switches between a first state in which supply of the heat medium to the terminal flow path is permitted and a second state in which supply is blocked, a hot water supply circuit that heats water supplied from the outside to supply hot water, A burner that burns gas, a heat exchanger heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path, and a heating circuit configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger. A control board communicably connected to a plurality of remote controls corresponding to the plurality of heat dissipation terminals. The control board includes a control device having a plurality of connection terminals, and a switching circuit capable of switching the remote control in a communication state with the control device. The switching circuit includes a remote control side connection portion electrically connected to each remote control, a control device side connection portion electrically connected to each connection terminal, a first transistor having a first control terminal and a pair of first main terminals, and a second transistor having a second control terminal and a pair of second main terminals. The plurality of control device side connection portions have a plurality of first ports and a plurality of second ports. The plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports. One of the pair of first main terminals in the first transistor is electrically connected to the remote control side connection portion, and the other is electrically connected to the input / output terminal. One of the pair of second main terminals in the second transistor is electrically connected to the first control terminal, the other is electrically connected to one of the first ports, and the second control terminal is electrically connected to one of the second ports. By the combination of the switching signals given to each first port and each second port, the remote control side connection portion communicably connected to the input / output terminal is switched to be selected from among the plurality of remote control side connection portions.

[0012] In the water heater and space heater described in [1] above, among a plurality of second ports, a switching signal consisting of a high-level signal or a low-level signal is input to any one of the second ports. In response to the switching signal, second control terminals of a plurality of second transistors connected to the second ports are turned on. With the second control terminals in the on state, among a plurality of first ports, a switching signal consisting of a high-level signal or a low-level signal is input to any one of the first ports. In response to the switching signal, the second transistor connected to the first port becomes in an energizable state, the first transistor connected to the second transistor is turned on, and communication is established between a remote control side connection portion connected to one main terminal of the first transistor and an input / output terminal of a control device connected to the other main terminal of the first transistor. Regarding the high-level signal and the low-level signal of the switching signal in the plurality of first ports connected to each second main terminal and the plurality of second ports connected to each second control terminal, by setting different combinations for each remote control of each heat dissipation terminal, the first transistors turned on by the switching signal input to the first control terminal can be sequentially switched, and the communication states between the remote controls of the plurality of heat dissipation terminals and the input / output terminals of the control device can be sequentially switched. As a result, for the water heater and space heater, it becomes possible to connect a number of remote controls equal to the product of the number of first ports and the number of second ports. Further, compared with a configuration in which the remote control side connection portion and the control device side connection portion are directly connected one-to-one, the number of connection terminals of the control device can be reduced, so that a shortage of connection terminals can be suppressed. Thereby, an increase in manufacturing cost due to an increase in the number of control devices associated with a shortage of connection terminals can be suppressed.

[0013] 〔2〕 A water heater and space heater configured to be able to supply the heat medium to a plurality of heat dissipation terminals having a terminal flow path through which the heat medium flows, and controlling a switching valve that switches between a first state that permits the supply of the heat medium to the terminal flow path and a second state that shuts off the supply, A hot water supply circuit that heats water supplied from the outside and supplies hot water, A burner that burns gas, a heat exchanger heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path, and a heating circuit configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger. A control board connected via communication means to a plurality of remote controls corresponding to the plurality of heat dissipation terminals. Comprising: The control board includes a control device having a plurality of connection terminals and a switching circuit capable of switching the remote control in communication with the control device. The switching circuit includes a remote control side connection part electrically connected to each remote control, a control device side connection part electrically connected to each connection terminal, and a plurality of transistors. The plurality of control device side connection parts have a plurality of first ports and a plurality of second ports. The plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports. The sum of the number of the plurality of first ports and the number of the plurality of second ports is less than the number of the plurality of remote control side connection parts. The switching circuit switches so as to select a remote control side connection part communicably connected to the input / output terminal from among the plurality of remote control side connection parts according to a combination of the switching signals given to each first port and each second port. A hot water heating machine.

[0014] The hot water heating machine according to [2] above has the same effect as the hot water heating machine according to [1] above and can suppress a shortage of the number of connection terminals of a control device for controlling the hot water heating machine.

[0015] (3) The first transistor is an NPN-type bipolar transistor. The second transistor is a PNP-type bipolar transistor. A plurality of sets of the second transistor and the first transistor are configured such that the collector of each of the second transistors is electrically connected to the base of each of the first transistors, the collector of the first transistor of each set is electrically connected to each of the remote control side connection portions, the emitter of the first transistor of each set is electrically connected to the input / output terminal, the emitter of the second transistor of each set is electrically connected to the first port, the emitter of the second transistor of each set is assigned to any one of the first ports such that the emitters of a plurality of the second transistors are electrically connected to each of the first ports, the base of the second transistor of each set is assigned to any one of the second ports such that the bases of a plurality of the second transistors are connected to each of the second ports, the first transistor and the second transistor of the set in which a high-level voltage is applied to the emitter of the second transistor and a low-level voltage is applied to the base of the second transistor are in an on state, the first transistor and the second transistor of the set in which at least either a low-level voltage is applied to the emitter of the second transistor or a high-level voltage is applied to the base of the second transistor are in an off state, communication becomes possible between the remote control side connection portion to which the collector of the first transistor of the set in which the first transistor and the second transistor are in an on state is electrically connected and the input / output terminal The hot water supply and space heating apparatus according to [1] or [2].

[0016] The water heater and heater described in [3] above uses a combination of an NPN bipolar transistor and a PNP bipolar transistor, and assigns the emitter of the second transistor in each pair to one of the first ports and the base of the second transistor in each pair to one of the second ports. With this simple configuration, while suppressing the number of the first ports and the second ports, it is possible to realize a configuration in which a larger number of remote control side connection parts can communicate individually with the input / output terminals.

[0017] 〔4〕The control device switches the combination of the switching signals given to the plurality of the first ports and the plurality of the second ports so that each of the plurality of the remote control side connection parts can communicate with the input / output terminals selectively with a time difference. The water heater and heater according to any one of [1] to [3] above.

[0018] The water heater and heater described in [4] above can make each of the plurality of remote control side connection parts communicate with the input / output terminals selectively with a time difference. Therefore, while suppressing the number of the first ports and the second ports, it is possible to make the remote control connected to each remote control side connection part communicate selectively and stably with the control device.

[0019] <First Embodiment> The following description relates to the water heater and heater 1 according to the first embodiment. 1. Overall Configuration of the Water Heater and Heater 1 FIG. 1 is a schematic circuit diagram of the water heater and heater 1. The water heater and heater 1 mainly includes a hot water supply circuit 2, a heating circuit 3, a bath circuit 4, etc., and is a device capable of performing a hot water supply operation, an automatic water filling operation, a supplementary heating operation, a heating operation, etc.

[0020] The hot water supply and heating machine 1 is provided with a housing 1A configured as a metal casing inside the housing, and a first combustion system unit 5 and a second combustion system unit 6 are configured inside the housing 1A. The housing 1A is configured as, for example, a metal can body or a metal box body, and is configured to accommodate a hot water supply burner 8A, a heating burner 33A, a hot water supply side heat exchanger 7, a heating side heat exchanger 32, and the like. The first combustion system unit 5 is a combustion system that performs gas combustion and water heating when the hot water supply circuit 2 performs a hot water supply operation. The second combustion system unit 6 is a combustion system that performs gas combustion and water heating during a heating operation or a supplementary heating operation.

[0021] The hot water supply circuit 2 is a circuit that heats water supplied from outside the hot water supply and heating machine 1 by the hot water supply side heat exchanger 7 and supplies hot water. The hot water supply circuit 2 includes the first combustion system unit 5, and specifically includes a plurality of hot water supply burners 8A and a hot water supply side heat exchanger 7. An ignition plug 85 and a flame sensor 86 are provided above the hot water supply burner 8A. The ignition plug 85 ignites the combustion gas by generating a spark discharge in response to an input signal from the controller 70, and the flame generated by the combustion is detected by the flame sensor 86. The first combustion system unit 5 is provided with a hot water supply combustion chamber 5A, and a hot water supply side burner unit 8 and a hot water supply side heat exchanger 7 are provided inside the hot water supply combustion chamber 5A. The hot water supply side burner unit 8 includes burner blocks 9A, 9B, and 9C, and each of the burner blocks 9A, 9B, and 9C includes a plurality of hot water supply burners 8A. Each of the plurality of hot water supply burners 8A is configured as a gas burner that burns gas.

[0022] The hot water supply side heat exchanger 7 is a heat exchanger heated by the exhaust gas generated by the hot water supply burner 8A. The hot water supply side heat exchanger 7 includes a first hot water supply side heat exchanger 7A and a second hot water supply side heat exchanger 7B. The first hot water supply side heat exchanger 7A has a plurality of fins 7Z. The first combustion system section 5 is provided with the first hot water supply side heat exchanger 7A above a plurality of hot water supply burners 8A, and the second hot water supply side heat exchanger 7B is provided above the first hot water supply side heat exchanger 7A. A pipeline 7C is connected between the downstream end of the second hot water supply side heat exchanger 7B and the upstream end of the first hot water supply side heat exchanger 7A, and the hot water flowing through the second hot water supply side heat exchanger 7B flows through the pipeline 7C to the first hot water supply side heat exchanger 7A. The hot water supply side heat exchanger 7 heats the water passing through the inside by the exhaust gas (combustion exhaust gas) generated by burning gas with a plurality of hot water supply burners 8A. The first hot water supply side heat exchanger 7A recovers sensible heat from the combustion exhaust gas discharged from the hot water supply side burner unit 8, and the second hot water supply side heat exchanger 7B recovers latent heat from the combustion exhaust gas discharged from the hot water supply side burner unit 8.

[0023] The hot water supply circuit 2 further includes a water supply pipe 11, a control valve 13A, a water flow sensor 14, a hot water outlet pipe 10, a bypass pipe 12, a control valve 13B, a thermistor 15A (hot water supply inner cylinder thermistor), a thermistor 15B (hot water supply outlet thermistor), etc. The water supply pipe 11 is connected to the inlet of the hot water supply side heat exchanger 7. The water supply pipe 11 is connected to an external pipe, and is configured as a pipeline that introduces tap water from, for example, a water supply and flows this tap water toward the upstream end (inlet) of the hot water supply side heat exchanger 7. The water flow sensor 14 is a sensor that detects the flow rate of the water flowing through the water supply pipe 11. The control valve 13A is a valve for controlling the flow rate of the water flowing through the water supply pipe 11, and is a valve that changes the opening degree of the water supply pipe 11 by control. The hot water outlet pipe 10 is connected to the downstream end (outlet) of the hot water supply side heat exchanger 7. The hot water outlet pipe 10 is a pipeline that flows the hot water heated by the hot water supply side heat exchanger 7. The hot water outlet pipe 10 forms a path for discharging the hot water heated by the hot water supply side heat exchanger 7 outside the appliance.

[0024] A bypass pipe 12 is connected between the water supply pipe 11 and the hot water outlet pipe 10 so as to bypass the hot water side heat exchanger 7. A control valve 13B (bypass control valve) is provided in the bypass pipe 12. The control valve 13B is a valve for controlling the flow rate of the water flowing through the bypass pipe 12, and specifically, it is configured as a valve that changes the opening degree of the bypass pipe 12 by control. A thermistor 15A is provided on the upstream side of the connection portion of the bypass pipe 12 in the hot water outlet pipe 10. The thermistor 15A detects the temperature of the hot water discharged from the hot water side heat exchanger 7, and specifically, detects the hot water temperature near the outlet of the first heat exchanger 7A on the hot water supply side. A thermistor 15B is provided on the downstream side of the connection portion of the bypass pipe 12. The thermistor 15B detects the hot water temperature after mixing of the water from the bypass pipe 12, and specifically, detects the temperature of the hot water supplied on the downstream side of the confluence point of the bypass pipe 12 in the hot water outlet pipe 10. The temperatures of the hot water detected by these thermistors 15A and 15B are input to a controller 70 described later.

[0025] The hot water supply circuit 2 further includes a gas pipe 16, a main gas solenoid valve 17, a gas proportional valve 18, and a solenoid valve 19. The gas pipe 16 is a pipe through which gas supplied from the outside of the hot water supply and heating machine 1 through the gas inlet passes, and forms a path for supplying gas to the hot water supply burner 8A. A main gas solenoid valve 17 is provided on the upstream side of the gas pipe 16, and a gas proportional valve 18 is provided on the downstream side of the main gas solenoid valve 17. The downstream side of the gas proportional valve 18 (hot water supply gas proportional valve) in the gas pipe 16 branches, and branch pipes 16A to each of the burner blocks 9A, 9B, 9C and branch pipes 16B to each of the burner blocks 34A, 34B are provided. An electromagnetic valve 19 is provided in each branch pipe 16A. The solenoid valve 19 (hot water supply switching solenoid valve) switches the branch pipe 16A between an open state (supply possible state) and a closed state (cut-off state), and the supply and cut-off of the fuel gas to each of the burner blocks 9A, 9B, 9C are individually switched by each solenoid valve 19. By switching the solenoid valve 19, the combustion range of the hot water supply side burner unit 8 is switched, and each combustion range is associated as a stage number.

[0026] The hot water supply circuit 2 further includes a fan 20. The fan 20 has a rotating body 20B that generates wind by its rotation and a drive source 20A that rotates the rotating body 20B. The fan 20 is provided below the hot water supply combustion chamber 5A. By the operation of the fan 20, combustion air is supplied to each hot water supply burner 8A and the heating burner 33A, and the combustion exhaust gas discharged from the hot water supply side burner unit 8 and the heating side burner unit 33 is discharged from the exhaust port 90. Near the fan 20, a current sensor 75 that detects the drive current of the fan 20 and a rotation speed sensor 76 that detects the rotation speed (rotational speed) of the fan 20 are provided. A signal corresponding to the drive current of the fan 20 detected by the current sensor 75 and a signal corresponding to the rotation speed of the fan 20 detected by the rotation speed sensor 76 are output to the controller 70. The hot water supply circuit 2 is also provided with an igniter for ignition, an ignition electrode, a hot water supply flame rod, and the like.

[0027] The bathtub circuit 4 includes a bathtub circulation path 63 and a bathtub heat exchanger 50. The bathtub circulation path 63 forms a flow path configured to circulate the hot water derived from an external bathtub 52 and introduce it into the bathtub 52. The bathtub heat exchanger 50 is configured as a liquid-liquid heat exchanger that performs heat exchange between the heat medium flowing through the bathtub heating pipe 51 and the hot water flowing through the bathtub circulation path 63.

[0028] The bathtub heat exchanger 50 is provided with a pipe 50A that forms part of the bathtub circulation path 63, and is configured such that the bathtub heating pipe 51 is disposed within the pipe 50A. The bathtub circulation path 63 is configured to include the pipe 50A, the bathtub supply pipe 53, and the bathtub return pipe 54. When the bathtub circulation pump 55 is operating, the bathtub circulation path 63 functions as a flow path for drawing out hot water from the bathtub 52 provided outside the hot water supply and heating apparatus 1, and also functions as a flow path for circulating the drawn-out hot water and introducing it into the bathtub 52. The bathtub return pipe 54 is provided with a bathtub circulation pump 55 for flowing the hot water within the bathtub return pipe 54 in a predetermined direction, and a water flow switch 57 for detecting that hot water having a flow rate equal to or greater than a predetermined value is flowing through the bathtub return pipe 54. The bathtub return pipe 54 is provided between the bathtub 52 outside the appliance and the pipe 50A, and forms a flow path for flowing hot water from the bathtub 52 to the pipe 50A when the bathtub circulation pump 55 is operating. The bathtub supply pipe 53 is provided between the pipe 50A and the bathtub 52, and forms a flow path for flowing hot water from the pipe 50A to the bathtub 52 when the bathtub circulation pump 55 is operating. The bathtub supply pipe 53 is provided with a bathtub supply thermistor 64 for detecting the temperature of the hot water flowing out from the bathtub heat exchanger 50 into the bathtub 52. The bathtub return pipe 54 is provided with a bathtub return thermistor 65 for detecting the temperature of the hot water flowing into the bathtub return pipe 54 from the bathtub 52.

[0029] The drain pipe 59 is connected to the bathtub return pipe 54 in a configuration branched from the hot water outlet pipe 10. The drain pipe 59 communicates with the bathtub return pipe 54. The drain pipe 59 is provided with a hot water supply solenoid valve 60, a drain water volume sensor 61, a plurality of check valves 62, and the like. When the hot water supply solenoid valve 60 provided in the drain pipe 59 is opened during the operation of the hot water supply circuit 2, the hot water heated by the hot water supply circuit 2 is supplied to the bathtub 52 through the drain pipe 59.

[0030] The heating circuit 3 is a circuit that can heat the heat medium by the heating-side heat exchanger 32 and supply the heat medium to the heating terminal (heat dissipation terminal) via the heat medium circulation path 48. In the present embodiment, the heat medium is, for example, hot water. Note that a fluid other than hot water may be used as the heat medium. The heating circuit 3 includes a second combustion system unit 6 and a heat medium circulation path 48. The second combustion system unit 6 is provided with a heating combustion chamber 6A, and a heating-side burner unit 33 and a heating-side heat exchanger 32 are provided in the heating combustion chamber 6A. The heating combustion chamber 6A is partitioned by a partition member 80 from the hot water supply combustion chamber 5A in the housing 1A, and a temperature sensor 82 for detecting the temperature of the heating combustion chamber 6A is provided on the partition member 80.

[0031] The heating-side burner unit 33 includes burner blocks 34A and 34B, and each of the burner blocks 34A and 34B includes a plurality of heating burners 33A (burners). Each of the plurality of heating burners 33A is configured as a gas burner that burns gas. An ignition plug 85 and a flame sensor 86 are provided above the heating burner 33A.

[0032] The heating-side heat exchanger 32 (heat exchanger) is a heat exchanger heated by the exhaust gas generated by the heating burner 33A. Specifically, it is a device that acts to heat the heat medium passing through its interior by the combustion exhaust gas of the heating burner 33A. The heating-side heat exchanger 32 includes a heating-side first heat exchanger 32A and a heating-side second heat exchanger 32B. The heating-side first heat exchanger 32A has a plurality of fins 32Z. The second combustion system unit 6 has the heating-side first heat exchanger 32A provided above a plurality of heating burners 33A, and the heating-side second heat exchanger 32B is provided above the heating-side first heat exchanger 32A. The heating-side heat exchanger 32 heats the heat medium passing through its interior by the exhaust gas (combustion exhaust gas) generated by burning gas with a plurality of heating burners 33A. The heating-side first heat exchanger 32A is supplied with the exhaust gas (combustion exhaust gas) generated by burning gas with the heating burner 33A (gas burner), and functions to heat the heat medium passing through the heating-side first heat exchanger 32A by the heat of this combustion exhaust gas. The heating-side first heat exchanger 32A recovers sensible heat from the combustion exhaust gas discharged from the heating-side burner unit 33. The heating-side second heat exchanger 32B is supplied with the gas after the combustion exhaust gas has passed through the heating-side first heat exchanger 32A, and functions to heat the heat medium passing through the heating-side second heat exchanger 32B by this gas. The heating-side second heat exchanger 32B recovers latent heat from the combustion exhaust gas discharged from the heating-side burner unit 33.

[0033] The heat medium circulation path 48 is a path for circulating the heat medium so as to pass through the heating-side heat exchanger 32, forming a flow path for the heat medium. The heat medium circulation path 48 includes a common forward flow path 38K as a heating forward pipe, a first internal flow path 38A as a heating high-temperature forward pipe, a second internal flow path 38B as a heating low-temperature forward pipe, and a common return flow path 38C as a heating return pipe.

[0034] As shown in Fig. 1, when the first heat dissipation terminal 39A as a heating terminal is connected, the heat medium circulation path 48 is configured to circulate the heat medium through the common forward flow path 38K, the first internal flow path 38A, the first terminal flow path 38G of the first heat dissipation terminal 39A, and the common return flow path 38C. When the second heat dissipation terminal 39Z as a heating terminal is connected as shown in Fig. 1, the heat medium circulation path 48 is configured to circulate the heat medium through the common forward flow path 38K, the second internal flow path 38B, the second terminal flow path 38H of the second heat dissipation terminal 39Z, and the common return flow path 38C.

[0035] The first internal flow path 38A is connected to the first heat dissipation terminal 39A as a flow path so as to communicate with the first terminal flow path 38G provided outside the water heater 1. The first internal flow path 38A is configured as a flow path branched from the branch portion 38J, and is configured as a flow path for flowing the heat medium from the branch portion 38J to the first heat dissipation terminal 39A. A part of the first internal flow path 38A is provided in the heating-side first heat exchanger 32A, and the heat medium flowing through the first internal flow path 38A is configured to be heated in the heating-side first heat exchanger 32A.

[0036] The second internal flow path 38B is connected to the second heat dissipation terminal 39Z as a flow path so as to communicate with the second terminal flow path 38H provided outside the water heater 1. The second internal flow path 38B is configured as a flow path branched from the branch portion 38J, and is configured as a flow path for flowing the heat medium from the branch portion 38J to the second heat dissipation terminal 39Z.

[0037] The heating circuit 3 further includes an expansion tank 36 corresponding to an example of a tank, a heating circulation pump 37 corresponding to an example of a pump, a heating high-temperature thermistor 40, and a heating low-temperature thermistor 41. The common return flow path 38C is a flow path through which the heat medium flowing into the inflow portion 35A returns to the expansion tank 36. In the example of FIG. 1, the upstream end of the common return flow path 38C is the inflow portion 35A, and the downstream end of the common return flow path 38C is connected to the inlet portion 36C of the expansion tank 36. The common return flow path 38C is configured as a pipe that introduces the heat medium exiting from the first heat dissipation terminal 39A or the second heat dissipation terminal 39Z into the interior through the inflow portion 35A and causes it to flow through the heating-side heat exchanger 32 (heating-side second heat exchanger 32B). The common return flow path 38C is configured to communicate with the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z, and is connected to the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z as a flow path for flowing the heat medium.

[0038] An intermediate pipe 38D and an intermediate pipe 38E are provided between the outlet of the heating-side second heat exchanger 32B and the inlet of the heating-side first heat exchanger 32A. In the paths of the intermediate pipes 38D and 38E, the expansion tank 36 and the heating circulation pump 37 are provided, and the heat medium can flow from the heating-side second heat exchanger 32B to the heating-side first heat exchanger 32A through the intermediate pipe 38D, the expansion tank 36, and the intermediate pipe 38E. The intermediate pipe 38D is a part of the common return flow path 38C and is a flow path between the outlet of the heating-side second heat exchanger 32B and the inlet portion 36C of the expansion tank 36. The intermediate pipe 38E is a pipe constituted by a part of the common forward flow path 38K and the first internal flow path 38A, and is provided between the outlet portion 36B of the expansion tank 36 and the inlet of the heating-side first heat exchanger 32A.

[0039] The common forward flow path 38K is configured as a flow path that introduces the heat medium flowing out from the outlet portion 36B and flows the heat medium flowing out from the expansion tank 36. A heating circulation pump 37 is provided in the middle of the common forward flow path 38K. The heating circulation pump 37 causes the heat medium in the common forward flow path 38K to flow from the expansion tank 36 side to the branch portion 38J side.

[0040] The second internal flow path 38B is provided in a configuration where a plurality of internal branch paths 38F branch off. A low-temperature switching valve 39G is provided in each internal branch path 38F as a valve for opening and closing each branch path 39F. In the example of FIG. 1, one internal branch path 38F communicates with the second heat radiation terminal 39Z and is connected to the second heat radiation terminal 39Z outside the appliance. The downstream sides of the first heat radiation terminal 39A and the second heat radiation terminal 39Z communicate with a common return flow path 38C. The first heat radiation terminal 39A is, for example, a high-temperature heating terminal such as a heating blower that blows warm air into a bathroom or a changing room. The second heat radiation terminal 39Z is, for example, a low-temperature heating terminal such as floor heating in a changing room.

[0041] The heating high-temperature thermistor 40 is provided in the first internal flow path 38A on the outlet side of the heating-side heat exchanger 32, and detects the temperature of the heat medium flowing out from the heating-side heat exchanger 32 (specifically, the heat medium flowing out from the first heating-side heat exchanger 32A). The temperature detected by the heating high-temperature thermistor 40 corresponds to the temperature of the heat medium flowing into the first heat radiation terminal 39A during the circulation of the heat medium passing through the first heat radiation terminal 39A. The heating low-temperature thermistor 41 is provided in the expansion tank 36. The temperature detected by the heating low-temperature thermistor 41 corresponds to the temperature of the heat medium flowing into the second heat radiation terminal 39Z during the circulation of the heat medium passing through the second heat radiation terminal 39Z.

[0042] The heating circuit 3 includes a plurality of branch pipes 16B and a plurality of heating switching solenoid valves 44. As described above, the branch pipe 16B is provided in a configuration branched from the gas pipe 16 to the heating circuit 3 side. Each heating switching solenoid valve 44 is provided in each branch pipe 16B. The heating switching solenoid valve 44 is configured to switch the branch pipe 16B in which it is provided between an open state (supply possible state) and a closed state (cut-off state). The supply and cut-off of the fuel gas to each of the burner blocks 34A, 34B are individually switched by each heating switching solenoid valve 44. By switching the heating switching solenoid valve 44, the combustion range of the heating-side burner unit 33 is switched, and each combustion range is associated as a number of stages. Note that the heating circuit 3 is also provided with an ignition electrode, a heating frame rod, and the like.

[0043] In the heating circuit 3, hot water heated by the heating-side heat exchanger 32 circulates through the heat medium circulation path 48 due to the operation of the heating circulation pump 37. Specifically, in the heating circuit 3, when the heating circulation pump 37 operates, the hot water flowing through the heat medium circulation path 48 is heated by the combustion exhaust gas discharged from the heating-side burner unit 33 in the heating-side heat exchanger 32, and circulates through the common return flow path 38C, the first internal flow path 38A, and the first heat dissipation terminal 39A, and also circulates through the common return flow path 38C, the second internal flow path 38B, and the second heat dissipation terminal 39Z. In the example of FIG. 1, hot water is supplied to the first heat dissipation terminal 39A according to the operation of the high-temperature switching valve 39H, which is a built-in thermostatic valve. The second heat dissipation terminal 39Z is configured as a low-temperature heating terminal, and hot water is supplied to the second heat dissipation terminal 39Z according to the operation of the low-temperature switching valve 39G, which is a thermostatic valve inside the appliance.

[0044] As shown in FIG. 1, the bath heating pipe 51 is provided in a configuration branched from the first internal flow path 38A. The bath heating pipe 51 branches from a position on the downstream side of the heating-side heat exchanger 32 in the heat medium circulation path 48 (specifically, on the downstream side of the heating-side first heat exchanger 32A), and forms a flow path that guides the heat medium flowing through the heat medium circulation path 48 to the bath heat exchanger 50 side. The bath heating pipe 51 is connected between the first internal flow path 38A and the common return flow path 38C so as to communicate with each other.

[0045] The control valve 58 is a valve provided on the upstream side of the bath heat exchanger 50 in the bath heating pipe 51. The control valve 58 is configured to open and close the bath heating pipe 51, and is configured to switch between a closed state that blocks the water flow passing through itself in the bath heating pipe 51 and an open state that allows the water flow passing through itself in the bath heating pipe 51. The control valve 58 has a switch. This switch is configured as a limit switch, and when the control valve 58 is in the fully open state where it is most open, it enters a first state in which a predetermined first signal (for example, a high-level signal) is output, and when the control valve 58 is in the fully closed state where it is blocked, it enters a second state in which a second signal (for example, a low-level signal) different from the first signal is output.

[0046] The water heating and heating device 1 further includes a controller 70, a hot water supply remote control 71, a bath remote control 72, a heating remote control 73, and a room temperature thermistor (not shown). The controller 70 is an electronic control device including an information processing device such as a CPU, a memory such as a semiconductor memory device, an interface circuit, etc., and functions as a controller for performing various controls. Various programs, data tables, set values, etc. are stored in the memory. The controller 70 is configured to be able to acquire signals from various sensors and switches (thermistors, water volume sensors, switches, etc.), and controls a hot water supply circuit 2, a heating circuit 3, a bath circuit 4, etc. The room temperature thermistor is provided as a temperature detection means for detecting the temperature in the dressing room, for example, inside the dressing room. Note that the controller 70 may be constituted by a single device (for example, a controller configured as a single unit), or may be constituted by a plurality of devices.

[0047] 2. Basic operation of the water heating and heating device 1 (Normal hot water supply operation) When the hot water supply faucet provided outside the device to communicate with the hot water outlet pipe 10 is opened and water flows into the appliance, and the water volume sensor 14 outputs a signal indicating the flow of water, the controller 70 rotates the fan 20 for a predetermined time to discharge the combustion exhaust gas stored in the hot water supply combustion chamber 5A (purging). Thereafter, the controller 70 opens the original gas solenoid valve 17 of the gas pipe 16 and each solenoid valve 19, and opens the gas proportional valve 18 at a predetermined opening degree to control the supply of gas to each hot water supply burner 8A, and operates the igniter to ignite the hot water supply burner 8A. When gas is burned by the hot water supply burner 8A by such control, the water passing through the hot water supply side heat exchanger 7 is heated by the combustion exhaust gas generated by the combustion and flows to the hot water outlet pipe 10, and the hot water heating operation is performed, and the heated hot water is discharged from the hot water supply faucet.

[0048] During the above hot water discharging operation, the controller 70 monitors the hot water temperature detected by the thermistor 15B provided in the hot water discharge pipe 10, and controls the opening and closing of the solenoid valve 19 and adjusts the opening degree of the gas proportional valve 18 so that the hot water temperature reaches the set temperature indicated by the hot water supply remote controller 71 or the bath remote controller 72. At the same time, the controller 70 continuously changes the air volume by controlling the rotational speed of the fan 20. When the hot water supply tap is closed during the above hot water discharging operation and the signal output by the water volume sensor 14 indicates a water flow stop state, the controller 70 closes the original gas solenoid valve 17 and the solenoid valve 19 to extinguish the hot water supply burner 8A, and rotates the fan 20 for a predetermined time to perform post-purge.

[0049] (Automatic hot water filling operation) The controller 70 can perform control to automatically fill the bathtub 52 with hot water. For example, when the hot water filling switch provided on the hot water supply remote controller 71 or the bath remote controller 72 is pressed, the controller 70 sets the hot water temperature to the hot water filling temperature set by the hot water supply remote controller 71 or the bath remote controller 72 as the target temperature (for example, 40 °C) and starts hot water filling. Specifically, the controller 70 opens the hot water supply solenoid valve 60 in the dropping pipe 59 to make the hot water supply circuit 2 in a water flow state, and burns the hot water supply burner 8A so that the heated hot water flows into the hot water discharge pipe 10. The hot water flowing through the hot water discharge pipe 10 in this way is supplied to the bathtub 52 through the dropping pipe 59 and the bath return pipe 54.

[0050] After the controller 70 starts supplying hot water to the bathtub 52 in this way, the controller 70 monitors whether the water volume detected by the dropping water volume sensor 61 provided in the dropping pipe 59 (the total water volume since the start of automatic hot water filling) has reached the set water volume. When it is confirmed that the set water volume has been reached, the controller 70 closes the hot water supply solenoid valve 60 to stop the water flow, extinguishes the hot water supply burner 8A, and ends the hot water filling. After that, the controller 70 operates the bath circulation pump 55 to circulate the hot water in the bathtub 52 in the bath circuit 4. When the hot water filling is completed, the controller 70 notifies the hot water supply remote controller 71 or the bath remote controller 72 of the end of the hot water filling.

[0051] (Automatic reheating operation) The controller 70 can perform control to automatically reheat (boil up) the water stored in the bathtub 52. For example, when the reheat switch provided on the hot water supply remote controller 71 or the bath remote controller 72 is pressed, the controller 70 sets the reheat temperature to the target temperature (e.g., 40 °C) set on the hot water supply remote controller 71 or the bath remote controller 72 and starts reheat. Specifically, the controller 70 ignites the heating burner 33A, opens the control valve 58, operates the bath circulation pump 55, and performs reheat by heating with the bath heat exchanger 50 while circulating the hot water in the bathtub 52. After starting such reheat, the controller 70 monitors whether the hot water temperature detected by the bath return thermistor 65 has reached the target temperature, and when it is confirmed that the temperature has reached, the controller 70 extinguishes the heating burner 33A, stops the bath circulation pump 55, and ends the reheat. When the controller 70 ends the reheat, it notifies the hot water supply remote controller 71 or the bath remote controller 72 of the end of the reheat.

[0052] 3. Configuration for supplying the heat medium to the heat dissipation terminals 39A and 39Z The hot water supply and heating machine 1 constitutes a hot water supply system while being connected to the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z, and supplies the heat medium branched by the internal branched flow path to the external first heat dissipation terminal 39A and the second heat dissipation terminal 39Z.

[0053] As shown in FIG. 1, the downstream end of the common flow path 38K in the heat medium circulation path 48 is a branch portion 38J. The branch portion 38J is a portion that branches the flow of the heat medium flowing through the common flow path 38K. The upstream side of the branch portion 38J is the common flow path 38K, and the downstream side of the branch portion 38J branches into a first internal flow path 38A and a second internal flow path 38B. The first internal flow path 38A has a reheat branch portion 56 that branches into the bath circuit 4, and on the bath circuit 4 side branched at the reheat branch portion 56, the bath heating pipe 51 passes through the bath heat exchanger 50 and is connected to the common return flow path 38C. The lower side (downstream side) of the reheat branch portion 56 has a connection portion 46B that branches into the bypass flow path 46.

[0054] The bypass flow path 46 is provided between the common return flow path 38C and the first internal flow path 38A. The bypass flow path 46 is a path through which the heat medium can flow so as to bypass between the common return flow path 38C and the first internal flow path 38A.

[0055] The downstream end of the first internal flow path 38A is configured to be connectable to the outside and is a first outflow portion 35B through which the heat medium flows out. The first outflow portion 35B is provided at the downstream end of the first internal flow path 38A and is configured as an outlet for flowing out the heat medium from the first internal flow path 38A toward the first terminal flow path 38G. The downstream end of the second internal flow path 38B is configured to be connectable to the outside and is a second outflow portion 35C through which the heat medium flows out. The second outflow portion 35C is provided at the downstream end of the second internal flow path 38B and is configured as an outlet for flowing out the heat medium from the second internal flow path 38B toward the second terminal flow path 38H. The upstream end of the common return flow path 38C is configured to be connectable to the outside and is an inflow portion 35A through which the heat medium flows in. The inflow portion 35A is provided downstream of the first terminal flow path 38G and downstream of the second terminal flow path 38H, and is an inlet through which the heat medium flowing through the first terminal flow path 38G flows in, and is also an inlet through which the heat medium flowing through the second terminal flow path 38H flows in.

[0056] Outside the hot water heater 1, a first heat dissipation terminal 39A to which the heat medium is supplied from the hot water heater 1 and which communicates with the heat medium circulation path 48, and a second heat dissipation terminal 39Z are provided. The first heat dissipation terminal 39A has a first terminal flow path 38G through which the heat medium flows, and dissipates the heat of the heat medium flowing through the first terminal flow path 38G. In the space near the first heat dissipation terminal 39A, the air is heated by the heat of the heat medium flowing through the first terminal flow path 38G being dissipated. The first heat dissipation terminal 39A is configured as a high-temperature heating terminal. The second heat dissipation terminal 39Z has a second terminal flow path 38H through which the heat medium flows, and dissipates the heat of the heat medium flowing through the second terminal flow path 38H. In the space near the second heat dissipation terminal 39Z, the air is heated by the heat of the heat medium flowing through the second terminal flow path 38H being dissipated. The downstream end of the first terminal flow path 38G and the downstream end of the second terminal flow path 38H are configured to be connectable so as to communicate with the inflow portion 35A of the hot water heater 1.

[0057] The supply of the heat medium to the first terminal flow path 38G is switched between a state where the supply of the heat medium is blocked and a state where it is permitted by the opening and closing of the high-temperature switching valve 39H. In the state where the high-temperature switching valve 39H is open (the first state), it is permitted for the heat medium to pass through the high-temperature switching valve 39H, and it is permitted for the heat medium to flow from the inside of the first internal flow path 38A, through the first terminal flow path 38G, to the downstream side (the inflow portion 35A side) of the high-temperature switching valve 39H. In the state where the high-temperature switching valve 39H is closed (the second state), it is blocked for the heat medium to pass through the high-temperature switching valve 39H, and the heat medium does not flow from the inside of the first internal flow path 38A to the downstream side of the high-temperature switching valve 39H. The supply of the heat medium to the second terminal flow path 38H is switched between a state where the supply of the heat medium is blocked and a state where it is permitted by the opening and closing of the low-temperature switching valve 39G. In the state where the low-temperature switching valve 39G is open (the first state), it is permitted for the heat medium to pass through the low-temperature switching valve 39G, and it is permitted for the heat medium to flow from the inside of the second internal flow path 38B, through the second terminal flow path 38H, to the downstream side (the inflow portion 35A side) of the low-temperature switching valve 39G. In the state where the low-temperature switching valve 39G is closed (the second state), it is blocked for the heat medium to pass through the low-temperature switching valve 39G, and the heat medium does not flow from the inside of the second internal flow path 38B to the downstream side of the low-temperature switching valve 39G. Both the high-temperature switching valve 39H and the low-temperature switching valve 39G are thermal valves. The thermal valve, for example, when the power is on, expands the expansion body with the heat of the heating element (Positive Temperature Coefficient) to push the piston and open the valve so that hot and cold water can flow, and when the power is off, the heating element naturally dissipates heat to contract the expansion body and close the valve.

[0058] The heat medium that has flowed into the inflow portion 35A circulates in the heat medium circulation path 48 inside the water heater 1. Specifically, the heat medium flows downstream from the inflow portion 35A through the common return flow path 38C, is heated by the heating-side second heat exchanger 32B, then passes through the expansion tank 36, and is further moved downstream by the power of the heating circulation pump 37. Then, the heat medium that has flowed toward the branch portion 38J is divided at the branch portion 38J into the heat medium going toward the first internal flow path 38A and the heat medium going toward the second internal flow path 38B. The heat medium flowing through the first internal flow path 38A is heated by the heating-side first heat exchanger 32A on the way.

[0059] The heat medium flowing through the first internal flow path 38A flows out toward the first terminal flow path 38G with the first outflow portion 35B as an outlet. The heat medium flowing through the second internal flow path 38B flows out as a heat medium toward the second terminal flow path 38H with the second outflow portion 35C as an outlet.

[0060] The high-temperature switching valve 39H that opens and closes the first terminal flow path 38G, the low-temperature switching valve 39G that opens and closes the second internal flow path 38B, and the heating circulation pump 37 are controlled by the controller 70. The controller 70 is electrically connected to each of the high-temperature switching valve 39H, the low-temperature switching valve 39G, and the heating circulation pump 37, and performs opening / closing control of the high-temperature switching valve 39H and the low-temperature switching valve 39G and drive control of the heating circulation pump 37.

[0061] 4. Configuration of the control device 70A and the switching circuit 91 FIG. 2 shows a control device 70A and a switching circuit 91 mounted on a control board 70B. The controller 70 (FIG. 1) of the hot water heater 1 includes a control board 70B conceptually shown in FIG. 2. The control board 70B is communicably connected to a plurality of heating remote controllers 73, which are an example of a remote controller (remote control), via communication means CA1 to CA10 such as communication cables. For example, a terminal provided on a first heating remote controller among the plurality of heating remote controllers 73 and a remote control side connection portion D1 are communicably connected (e.g., short-circuited) via the communication means CA1, and a signal output from the remote control side connection portion D1 is input to the terminal provided on the first heating remote controller, and a signal output from the terminal provided on the first heating remote controller is input to the remote control side connection portion D1. Similarly, a terminal provided on a second heating remote controller among the plurality of heating remote controllers 73 and a remote control side connection portion D2 are communicably connected (e.g., short-circuited) via the communication means CA2, and a signal output from the remote control side connection portion D2 is input to the terminal provided on the second heating remote controller, and a signal output from the terminal provided on the second heating remote controller is input to the remote control side connection portion D2. The same applies to each of the other remote control side connection portions D3 to D10, and each of the other plurality of heating remote controllers is communicably connected via communication means. Note that in FIG. 1, one heating remote controller 73 is shown, and the other heating remote controllers 73 are omitted. The plurality of heating remote controllers 73 are provided in each room corresponding to, for example, floor heating as a plurality of second heat dissipation terminals 39Z.

[0062] The control board 70B includes a control device 70A having a plurality of connection terminals (switching terminals T1 to T7 and input / output terminals T8, T9), and a switching circuit 91 capable of switching a heating remote controller 73 in communication with the control device 70A. The control device 70A is an information processing device such as a microcomputer, for example, and a plurality (a large number) of connection terminals (switching terminals T1 to T7 and input / output terminals T8, T9) are provided side by side on the outer peripheral edge side of the control device main body. Although a large number of the plurality of connection terminals (switching terminals T1 to T7 and input / output terminals T8, T9) are formed over the entire circumference of the control device 70A, in FIG. 2, nine connection terminals (switching terminals T1 to T7 and input / output terminals T8, T9) are shown in a simplified configuration in the drawing, and the other large number of connection terminals are omitted.

[0063] In this specification, "electrically connected" means connected so as to be able to transmit signals, and includes any of a configuration connected so that a signal is transmitted at the same level, a configuration connected so that the level of the signal is increased or decreased and transmitted, and a configuration connected so that the signal is transmitted in an inverted manner.

[0064] The above-mentioned plurality of connection terminals include a plurality of switching terminals T1 to T7 and input / output terminals T8 and T9. The plurality of switching terminals T1 to T7 are electrically connected to a plurality of first ports A1 to A4 and a plurality of second ports B1 to B3 in the switching circuit 91, and output a switching signal composed of a high-level signal or a low-level signal. Specifically, the switching terminal T1 is electrically connected (for example, short-circuited) to the first port A1, the switching terminal T2 is electrically connected (for example, short-circuited) to the second port B1, the switching terminal T3 is electrically connected (for example, short-circuited) to the second port B2, the switching terminal T4 is electrically connected (for example, short-circuited) to the second port B3, the switching terminal T5 is electrically connected (for example, short-circuited) to the first port A2, the switching terminal T6 is electrically connected (for example, short-circuited) to the first port A3, and the switching terminal T1 is electrically connected (for example, short-circuited) to the first port A4. For example, when a high-level signal is applied to the switching terminal T1, a high-level signal is also input to the first port A1, and when a low-level signal is applied to the switching terminal T1, a low-level signal is also input to the first port A1. The input / output terminals T8 and T9 are electrically connected to the input / output parts AX1 and AX2 in the switching circuit 91, and input / output input / output signals. In this specification, the input part AX1 and the output part AX2 are collectively referred to as the input / output parts AX1 and AX2. In the example of FIG. 2, the terminal T8 is electrically connected (for example, short-circuited) to the input part AX1, and the terminal T9 is electrically connected (for example, short-circuited) to the output part AX2. The input / output terminals T8 and T9 perform input, etc. of control signals for controlling various devices of the hot water heater 1 between the heating remote controller 73.

[0065] FIG. 3 shows the circuit configuration of the switching circuit 91. As shown in FIG. 3, the switching circuit 91 includes a plurality of remote control side connection parts D1 to D10, a plurality (seven in this embodiment) of control device side connection parts (first ports A1 to A4, second ports B1 to B3), a plurality (ten in this embodiment) of first transistors TR1A to TR10A, and a plurality (ten in this embodiment) of second transistors TR1B to TR10B. The plurality of remote control side connection parts D1 to D10 are communicably connected to each of the heating remote controls 73 via each of the communication means CA1 to CA10. The plurality of control device side connection parts are configured to be connected to connection terminals T1 to T9, and the plurality of first ports A1 to A4 and the plurality of second ports B1 to B3 are provided.

[0066] As shown in FIG. 3, each of the first transistors TR1A to TR10A is an NPN-type bipolar transistor and has a base B which is an example of a first control terminal, and a collector C and an emitter E which are examples of a pair of first main terminals. Each of the first transistors TR1A to TR10A includes a base B-side resistor R1 and a base-emitter resistor R2. In the example of FIG. 3, a collector C, which is one of the pair of first main terminals in each of the first transistors TR1A to TR10A, is electrically connected in a configuration short-circuited to each of the remote control side connection parts D1 to D10. An emitter E, which is the other of the pair of first main terminals in each of the first transistors TR1A to TR10A, is communicably (signal-transmittably) connected to input / output parts AX1, AX2 and input / output terminals T8, T9 via a forward diode D. Specifically, the emitter of each of the first transistors TR1A to TR10A is electrically connected in a configuration short-circuited to the anode of the corresponding diode D among the plurality of diodes D, and the cathodes of each of the plurality of diodes D are electrically connected in a configuration short-circuited to a common signal line (the signal line between the plurality of diodes D and BT2, 3).

[0067] Each of the second transistors TR1B to TR10B is a PNP bipolar transistor and has a base B which is an example of a second control terminal, and a collector C and an emitter E which are examples of a pair of second main terminals. Each of the second transistors TR1B to TR10B includes a resistor R1 on the base B side and a resistor R2 between the base and the emitter. In each of the second transistors TR1B to TR10B, a collector C, which is one of the pair of second main terminals, is connected to the base B via the resistor R2, and an emitter E is connected to each of the first ports A1 to A4. Specifically, each of the second transistors TR1B to TR10B is electrically connected in such a configuration that one end of the correspondingly provided resistor R2 is short-circuited to the base B and the other end of the resistor R2 is short-circuited to the emitter E. The base B of each of the second transistors TR1B to TR10B is connected to the second ports B1 to B3 via forward diodes DB1 to DB10, respectively. Specifically, each of the second transistors TR1B to TR10B is electrically connected in such a configuration that one end of the correspondingly provided resistor R1 is short-circuited to the base B, and the other end of the resistor R1 is electrically connected in such a configuration that it is short-circuited to the anode of any one of the diodes DB1 to DB10 provided correspondingly.

[0068] In the switching circuit 91, a wiring pattern for connecting the remote control side connection portions D1 to D10, the first transistors TR1A to TR10A, and the second transistors TR1B to TR10B so that signal transmission is possible forms the first wiring portion to the tenth wiring portion corresponding to the remote control side connection portions D1 to D10.

[0069] More specifically, in the switching circuit 91, a plurality of pairs are formed between each of the second transistors TR1B to TR10B and each of the first transistors TR1A to TR10A such that the collector of each of the second transistors TR1B to TR10B is electrically connected (specifically, electrically connected via a short circuit or a resistance component) to the base of each of the first transistors TR1A to TR10A. In the example of FIG. 3, for example, a pair of the second transistor TR1B and the first transistor TR1A is formed such that the collector of the second transistor TR1B is electrically connected to the base of the first transistor TR1A via the resistor R1 (one end of the resistor R1 is short-circuited to the collector of the second transistor TR1B and the other end is short-circuited to the base of the first transistor TR1A). Similarly, a pair of the second transistor TR2B and the first transistor TR2A is formed such that the collector of the second transistor TR2B is electrically connected to the base of the first transistor TR2A via the resistor R1 (one end of the resistor R1 is short-circuited to the collector of the second transistor TR2B and the other end is short-circuited to the base of the first transistor TR2A). Similarly, a pair of the second transistor TR3B and the first transistor TR3A is formed such that the collector of the second transistor TR3B is electrically connected to the base of the first transistor TR3A via the resistor R3 (one end of the resistor R1 is short-circuited to the collector of the second transistor TR3B and the other end is short-circuited to the base of the first transistor TR3A). Thus, pairs of the first transistor and the second transistor are formed corresponding to the number of the remote control side connection portions D1 to D10.

[0070] And the collector of each of the first transistors TR1A to TR10A in each pair is connected to each of the remote control side connection portions D1 to D10 so as to be capable of signal transmission. Specifically, when any one of the first transistors TR1A to TR10A is turned on, the input / output portions AX1, AX2 (and the input / output terminals T8, T9) and the remote control side connection portion electrically connected to the turned-on first transistor are connected via the first transistor so as to be capable of communication. In the example of FIG. 3, the collectors of each of the first transistors TR1A to TR10A are short-circuited to each of the remote control side connection portions D1 to D10.

[0071] Furthermore, the emitters of the first transistors TR1A to TR10A in each group are connected to the input / output sections AX1, AX2 (and the input / output terminals T8, T9) so as to be able to transmit signals thereto. Specifically, when any one of the first transistors TR1A to TR10A is in an on state, the input / output sections AX1, AX2 (and the input / output terminals T8, T9) and the remote control side connection section electrically connected to the on-state first transistor are connected via the first transistor so as to be able to communicate with each other.

[0072] The emitter of each of the second transistors TR1B to TR10B in each group is electrically connected to any one of the plurality of first ports A1 to A4. Specifically, the emitter of each of the second transistors TR1B to TR10B in each group is assigned to any one of the plurality of first ports A1 to A4 so that the emitter of each of the second transistors TR1B to TR10B can be connected to each of the plurality of first ports A1 to A4 for signal transmission. Specifically, as shown in FIG. 3, the first port A1 is assigned to the emitters of the second transistors TR1B, TR2B, and TR3B, the first port A2 is assigned to the emitters of the second transistors TR4B, TR5B, and TR6B, the first port A3 is assigned to the emitters of the second transistors TR7B and TR8B, and the first port A4 is assigned to the emitters of the second transistors TR9B and TR10B. For example, when an active signal (low-level signal) described later is input to the first port A1, this active signal (low-level signal) is inverted by the inverting amplifier circuit BR1, and a high-level voltage is applied to the emitters of the second transistors TR1B, TR2B, and TR3B assigned corresponding to the first port A1. When a high-level signal is input to the first port A1, this high-level signal is inverted by the inverting amplifier circuit BR1, and a low-level voltage is applied to the emitters of the second transistors TR1B, TR2B, and TR3B. Similarly, when an active signal (low-level signal) described later is input to the first port A2, this active signal (low-level signal) is inverted by the inverting amplifier circuit BR2, and a high-level voltage is applied to the emitters of the second transistors TR4B, TR5B, and TR6B assigned corresponding to the first port A2. When a high-level signal is input to the first port A2, this high-level signal is inverted by the inverting amplifier circuit BR2, and a low-level voltage is applied to the emitters of the second transistors TR4B, TR5B, and TR6B.

[0073] For each of the plurality of second ports B1 to B3, the bases of each of the plurality of second transistors TR1B to TR10B are assigned to any one of the plurality of second ports B1 to B3 such that the bases of each of the sets of second transistors TR1B to TR10B are connected. Specifically, as shown in FIG. 3, the second port B1 is assigned to the bases of the second transistors TR1B, TR4B, TR7B, TR9B, the second port B2 is assigned to the bases of the second transistors TR2B, TR5B, TR8B, TR10B, and the second port B3 is assigned to the bases of the second transistors TR3B, TR6B. For example, when an active signal (high-level signal) described later is input to the second port B1, this active signal (high-level signal) is inverted by the inverting amplifier circuit BS1, and a low-level voltage is applied to the cathodes of the diodes DB1, DB4, DB7, DB9 that are electrically connected to the bases of the second transistors TR1B, TR4B, TR7B, TR9B assigned corresponding to the second port B1. When a low-level signal is input to the second port B1, this low-level signal is inverted by the inverting amplifier circuit BS1, and a high-level voltage is applied to the cathodes of the diodes DB1, DB4, DB7, DB9. Similarly, when an active signal (high-level signal) described later is input to the second port B2, this active signal (high-level signal) is inverted by the inverting amplifier circuit BS2, and a low-level voltage is applied to the cathodes of the diodes DB2, DB5, DB8, DB10 that are electrically connected to the bases of the second transistors TR2B, TR5B, TR8B, TR10B assigned corresponding to the second port B2. When a low-level signal is input to the second port B2, this low-level signal is inverted by the inverting amplifier circuit BS1, and a high-level voltage is applied to the cathodes of the diodes DB2, DB5, DB8, DB10.

[0074] Between the remote control side connection parts D1 to D10 and the collectors C of the first transistors TR1A to TR10A, they are connected by signal lines composed of conductive paths such as the wiring patterns of the control board 70B. One end side of each of the varistors V1 to V10 and one end side of each of the capacitors C1 to C10 are connected to each of these signal lines. The other end side of each of the varistors V1 to V10 is connected to the ground. The other end side of each of the capacitors C1 to C10 is connected to the remote control side connection terminal DX.

[0075] The emitters E of the second transistors TR1B to TR10B are connected (connected so as to be able to transmit signals) to the first ports A1 to A4 via the inverting amplifier circuits BR1 to BR4. The bases B of the second transistors TR1B to TR10B are connected (connected so as to be able to transmit signals) to the second ports B1 to B3 via the inverting amplifier circuits BS1 to BS3. The high-level signals output from the first ports A1 to A4 and the second ports B1 to B3 are converted into low-level signals by the inverting amplifier circuits BR1 to BR4 and BS1 to BS3, and the low-level signals output from the first ports A1 to A4 and the second ports B1 to B3 are converted into high-level signals by the inverting amplifier circuits BR1 to BR4 and BS1 to BS3 and output to the bases B and collectors C of the second transistors TR1B to TR10B.

[0076] Between the emitters E of the second transistors TR1B to TR10B and each of the inverting amplifier circuits BR1 to BR4, each signal line (the signal line connected to the output side of each of the inverting amplifier circuits BR1 to BR4) is configured such that one end of a resistor R is connected to the reference voltage line VL1 and the other end is connected to the signal line, and a voltage from the reference voltage line VL1 is applied. One end of a capacitor C is connected to each signal line, and the other end of the capacitor is connected to ground. The remote control side connection parts D1 to D10 are connected so as to be able to communicate with the input / output parts AX1, AX2 via the first transistors TR1A to TR10A, the diodes D, the inverting amplifier circuits BT1, BT3 or the inverting amplifier circuit BT2. Between each diode D and the input part AX1, inverting amplifier circuits BT1, BT3 are provided, and between each diode D and the output part AX2, an inverting amplifier circuit BT2 is provided. Specifically, for example, when the control device 70A receives signals from the remote control side connection parts D1 to D10, a voltage corresponding to the voltage (high-level voltage or low-level voltage) applied to the signal line L is input to the input part AX1 and the terminal T8. When the control device 70A outputs signals to the remote control side connection parts D1 to D10, a voltage obtained by inverting the voltage (high-level voltage or low-level voltage) applied to the output part AX2 and the terminal T8 is applied to the signal line L. Note that the input / output configuration described here (the configuration for signal transmission between the emitters of the first transistors TR1A to TR10A and the input / output parts AX1, AX2) is merely an example, and other configurations may be used as long as signals can be transmitted between the emitters of the first transistors TR1A to TR10A and the input / output parts AX1, AX2.

[0077] 5. Operations of the control device 70A and the switching circuit 91 FIG. 4 shows the relationship between the active first port, the active second port, the second transistor to which a high-level voltage is applied to the emitter, the second transistor to which a low-level voltage is applied to the base, and the first transistor to which a high-level voltage is applied to the base. The first ports A1 to A4 are low-active, and the second ports B1 to B3 are high-active. For example, when the control device 70A outputs a high-level signal (e.g., a voltage signal of 5 [V]) from the switching terminal T2, a high-level signal (active signal) is input to the second port B1 of the switching circuit 91 connected to the switching terminal T2. The high-level signal of the second port B1 is converted into a low-level signal by the inverting amplifier circuit BS1, and a low-level signal (e.g., a voltage signal of 0 [V]) is input to the cathode of the diode DB1 electrically connected to the base B of the second transistor TR1B. In this state, when the control device 70A outputs a low-level signal (e.g., a voltage signal of 0 [V]) from the switching terminal T1, a low-level signal (active signal) is input to the first port A1 of the switching circuit 91 connected to the switching terminal T1. The low-level signal of the first port A1 is converted into a high-level signal by the inverting amplifier circuit BR1, and a high-level voltage is applied to the emitter E of the second transistor TR1B. Therefore, the second transistor TR1B has a base current flowing and becomes an on state, and the emitter-collector of the second transistor TR1B is in a conductive state where current can flow. When current flows between the emitter and collector of the second transistor TR1B, a base current flows in the first transistor TR1A, and the collector-emitter of the first transistor TR1A is in a conductive state where current can flow. Since the collector-emitter of the first transistor TR1A is in a conductive state in this way, communication between the remote control side connection portion D1 and the input / output portions AX1 and AX2 is possible via the diode D and the communication line L. On the other hand, when a high-level signal is input to the first port A1 or a low-level signal is input to the second port B1, the first transistor TR1A and the second transistor TR1B do not become on states, and in either case, the energization between the emitter and collector is cut off, so communication between the remote control side connection portion D1 and the input / output terminals T8 and T9 is not established.

[0078] Also, when a high-level signal (e.g., a voltage signal of 5 [V]) is output from the switching terminal T3 of the control device 70A, the high-level signal (active signal) is input to the second port B2 of the switching circuit 91 connected to the switching terminal T3. The high-level signal of the second port B2 is converted into a low-level signal by the inverting amplifier circuit BS2, and a low-level signal (e.g., a voltage signal of 0 [V]) is input to the cathode of the diode DB2 electrically connected to the base B of the second transistor TR2B. In this state, when a low-level signal (e.g., a voltage signal of 0 [V]) is output from the switching terminal T1 of the control device 70A, the low-level signal (active signal) is input to the first port A1 of the switching circuit 91 connected to the switching terminal T1. The low-level signal of the first port A1 is converted into a high-level signal by the inverting amplifier circuit BR1, and a high-level voltage is applied to the emitter E of the second transistor TR2B. Therefore, the second transistor TR2B has a base current flowing and becomes in an on state, and the emitter-collector interval of the second transistor TR2B is in a conductive state where current can flow. When current flows between the emitter and collector of the second transistor TR2B, a base current flows in the first transistor TR2A, and the collector-emitter interval of the first transistor TR2A is in a conductive state where current can flow. Since the collector-emitter interval of the first transistor TR2A thus becomes in a conductive state, communication between the remote control side connection part D2 and the input / output parts AX1, AX2 can be established via the diode D and the communication line L. On the other hand, when a high-level signal is input to the first port A1 or a low-level signal is input to the second port B2, the first transistor TR2A and the second transistor TR2B do not become in an on state, and in any case, the energization between the emitter and collector is interrupted, so communication between the remote control side connection part D2 and the input / output terminals T8, T9 is not established. The same applies to the other remote control side connection parts D3 to D10, and communication between the remote control side connection part D2 and the input / output terminals T8, T9 is established by the combination of the high-level signals and low-level signals of the first ports A1 to A4 and the second ports B1 to B3.

[0079] FIG. 5 shows the correspondence relationship of which of the remote control side connection parts D1 to D10 can communicate depending on the combination of the ports that become active at the first ports A1 to A4 and the ports that become active at the second ports B1 to B3. As described above, the first ports A1 to A4 are low-active, and the second ports B1 to B3 are high-active. For example, when a low-level signal (active signal) is output from the first port A1 of the control device 70A and a high-level signal (active signal) is output from the second port B1, communication is established between the remote control side connection part D1 and the input / output terminals T8 and T9 of the control device 70A via the input / output parts AX1 and AX2, and mutual communication between the heating remote control 73 and the control device 70A becomes possible. Also, when a low-level signal is output from the first port A1 and a high-level signal is output from the second port B2, communication is established between the remote control side connection part D2 and the input / output terminals T8 and T9 of the control device 70A via the input / output parts AX1 and AX2, and mutual communication between the heating remote control 73 and the control device 70A becomes possible. Also, when a low-level signal is output from the first port A4 and a high-level signal is output from the second port B2, communication is established between the remote control side connection part D10 and the input / output terminals T8 and T9 of the control device 70A via the input / output parts AX1 and AX2, and mutual communication between the heating remote control 73 and the control device 70A becomes possible. In this way, the remote control side connection parts D1 to D10 that can communicate are switched in order. Note that since the remote control side connection parts D1 to D10 can be formed by the number obtained by multiplying the number of the first ports A1 to A4 by the number of the second ports B1 to B3, when using the first ports A1 to A4 and the second ports B1 to B3, it is possible to form a maximum of 12 remote control side connection parts. However, in the case of this embodiment, 10 remote control side connection parts D1 to D10 are formed.

[0080] As described above, the switching circuit 91 operates such that the first transistor and the second transistor in the set where a high-level voltage is applied to the emitter of the second transistor and a low-level voltage that is relatively lower than the emitter voltage is applied to the base of the second transistor are turned on. Then, the remote control side connection portion to which the collector of the first transistor in the set where the first transistor and the second transistor are turned on is electrically connected and the input / output terminals T8 and T9 operate so as to be able to communicate with each other.

[0081] Then, the control device 70A switches the combination of switching signals applied to the plurality of first ports A1 to A4 and the plurality of second ports B1 to B3 so that each of the plurality of remote control side connection parts D1 to D10 can communicate with the input / output terminals T8 and T9 alternately with a time difference. Specifically, for example, in the order in which the remote control side connection parts D1 to D10 are arranged, only the combination of the first port A1 and the second port B1 is made active so that only the remote control side connection part D1 can communicate with the input / output parts AX1 and AX2 for a certain period of time (for example, 0.1 second). After that, only the combination of the first port A1 and the second port B2 is made active so that only the remote control side connection part D2 can communicate with the input / output parts AX1 and AX2 for a certain period of time (for example, 0.1 second). Then, only the combination of the first port A1 and the second port B3 is made active so that only the remote control side connection part D3 can communicate with the input / output parts AX1 and AX2 for a certain period of time (for example, 0.1 second). That is, by operating so that the second ports B1, B2, and B3 are sequentially made active every certain period of time (for example, 0.1 second) with the first port A1 fixed to be active, the remote control side connection parts D1, D2, and D3 can be made to communicate with the input / output parts AX1 and AX2 alternately and sequentially. Next, by operating so that the second ports B1, B2, and B3 are sequentially made active every certain period of time (for example, 0.1 second) with the first port A2 fixed to be active, the remote control side connection parts D4, D5, and D6 can be made to communicate with the input / output parts AX1 and AX2 alternately and sequentially. After that, by operating so that the second ports B1 and B2 are sequentially made active every certain period of time (for example, 0.1 second) with the first port A3 fixed to be active, the remote control side connection parts D7 and D8 can be made to communicate with the input / output parts AX1 and AX2 alternately and sequentially. By operating so that the second ports B1 and B2 are sequentially made active every certain period of time (for example, 0.1 second) with the first port A4 fixed to be active, the remote control side connection parts D9 and D10 can be made to communicate with the input / output parts AX1 and AX2 alternately and sequentially.Note that the control device 70A does not transmit signals in the combinations where the first port A3 is active and the second port B3 is active, and where the first port A4 is active and the second port B3 is active. By adopting such a method, with a configuration that suppresses the number of terminals for switching, the control device 70A can communicate with more remote control side connection parts via the input / output parts AX1 and AX2, and thus can communicate with more remote controls. However, since the control device 70A and each remote control communicate with a time difference, a slight delay will occur. However, for an operation of switching every 0.1 seconds as described above, even if 10 switches are made, the delay is about 1 second, so it does not cause much of a problem in the application where the water heater 1 communicates with an external remote control.

[0082] 6. Examples of effects The control board 70B of the water supply and heating unit 1 includes a control device 70A having a plurality of connection terminals T1 to T9, and a switching circuit 91 capable of switching a heating remote controller 73 in communication with the control device 70A. The switching circuit 91 includes a plurality of remote controller side connection parts D1 to D10 connected to each heating remote controller 73 side, a plurality of control device side connection parts (first ports A1 to A4, second ports B1 to B3) having a plurality of first ports A1 to A4 and a plurality of second ports B1 to B3 connected to each connection terminal T1 to T9, first transistors TR1A to TR10A having a base B (first control terminal) and an emitter E and a collector C (a pair of first main terminals), and second transistors TR1B to TR10B having a base B (second control terminal) and an emitter E and a collector C (a pair of second main terminals). The plurality of connection terminals T1 to T9 in the control device 70A include input / output terminals T8 and T9 for inputting or outputting information to and from the heating remote controller 73, and a plurality of switching terminals T1 to T7 for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports A1 to A4 and the plurality of second ports B1 to B3. Among the pair of first main terminals of the first transistors TR1A to TR10A, the collector (one side) is connected to the remote controller side connection parts D1 to D10, and the emitter (the other side) is connected to the input / output terminals T8 and T9. In the second transistors TR1B to TR10B, the collector C (one of the pair of second main terminals) is connected to the base B (first control terminal) of the first transistors TR1A to TR10A, the emitter E (the other side) is connected to any one of the first ports A1 to A4, the base B (second control terminal) of the second transistors TR1B to TR10B is connected to any one of the second ports B1 to B3, and the plurality of first ports A1 to A4 connected to the emitter E (second main terminal) of each second transistor TR1B to TR10B and the plurality of second ports B1 to B3 connected to the base B (second control terminal) of each second transistor TR1B to TR10B are configured such that the remote controller side connection parts D1 to D10 communicably connected to the input / output terminals T8 and T9 among the plurality of remote controller side connection parts D1 to D10 are switched by a combination of the high-level signal and the low-level signal of the switching signal.

[0083] Among a plurality of second ports B1 to B3, a switching signal composed of a high-level signal or a low-level signal is input to any one of the second ports B1 to B3. According to the switching signal, the bases B (second control terminals) of a plurality of second transistors TR1B to TR10B connected to the second ports B1 to B3 are turned on. With the bases B (second control terminals) of the second transistors TR1B to TR10B turned on, a switching signal composed of a high-level signal or a low-level signal is input to any one of a plurality of first ports A1 to A4. According to the switching signal, the second transistors TR1B to TR10B connected to the first ports A1 to A4 become in a state where they can be energized, the first transistors TR1A to TR10A connected to the second transistors TR1B to TR10B are turned on, and communication is established between the remote control side connection portions D1 to D10 connected to the emitters E (one of the main terminals) of the first transistors TR1A to TR10A and the input / output terminals T8 and T9 of the control device 70A connected to the collectors C (the other main terminals) of the first transistors TR1A to TR10A.

[0084] For the high-level and low-level signals of the switching signal in the plurality of first ports A1 to A4 connected to each second main terminal and the plurality of second ports B1 to B3 connected to the bases B (second control terminals) of the second transistors TR1B to TR10B, by setting different combinations for each remote controller 73 of the second heat dissipation terminals 39Z, the first transistors TR1A to TR10A that are turned on by the switching signal input to the bases B (first control terminals) of the first transistors TR1A to TR10A can be sequentially switched, and the communication state between the heating remote controllers 73 of the plurality of second heat dissipation terminals 39Z and the input / output terminals T8 and T9 of the control device 70A can be sequentially switched. As a result, for the hot water heating machine 1, it becomes possible to connect the heating remote controllers 73 in a number equal to the product of the number of the first ports A1 to A4 and the number of the second ports B1 to B3. Also, compared with a configuration in which the remote controller side connection parts D1 to D10 and the control device 70A are directly connected (without providing the switching circuit 91), the number of connection terminals T1 to T9 of the control device 70A can be reduced, so that a shortage of the number of connection terminals T1 to T9 can be suppressed. Thereby, an increase in the manufacturing cost due to an increase in the number of the control devices 70A associated with a shortage of the number of connection terminals T1 to T9 can be suppressed.

[0085] <Other Embodiments> The present invention is not limited to the embodiments described by the above description and drawings. For example, the features of the above-described or later-described embodiments can be combined in any combination within a non-contradictory range. Also, any feature of the above-described or later-described embodiments can be omitted if it is not explicitly specified as essential. Furthermore, the above-described embodiments may be modified as follows.

[0086] The numbers of the remote control side connection parts D1 to D10, the first transistors TR1A to TR10A, the second transistors TR1B to TR10B, the first ports A1 to A4, the second ports B1 to B3, etc. are not limited to the numbers in the above-described embodiment, and can be appropriately changed according to the number of the heating remote control 73, etc. and the number of connection terminals of the control device 70A. In addition, although the first transistors TR1A to TR10A and the second transistors TR1B to TR10B are bipolar transistors, the present invention is not limited thereto. For example, an FET (Field Effect Transistor) may be used for one or both of the first transistor and the second transistor.

[0087] It should be considered that all the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is not limited to the embodiments disclosed this time, and it is intended that all modifications within the scope indicated by the claims or within the scope equivalent to the claims are included.

Explanation of Signs

[0088] 1: Water heater 2: Hot water supply circuit 3: Heating circuit 32: Heating side heat exchanger (heat exchanger) 33A: Heating burner (burner) 39A: First heat dissipation terminal (heat dissipation terminal) 39Z: Second heat dissipation terminal (heat dissipation terminal) 38G: First terminal flow path (terminal flow path) 38H: Second terminal flow path (terminal flow path) 39H: High temperature switching valve (switching valve) 39G: Low temperature switching valve (switching valve) 48: Heat medium circulation path 70A: Control device 70B: Control board 91: Switching circuit A1~A4: First port (control device side connection part) B1~B3: Second port (control device side connection part) CA1~CA10: Communication means D1~D10: Remote control side connection part T1~T9: Connection terminals T8, T9: Input / output terminals TR1A~TR10A: First transistors TR1B~TR10B: Second transistors B: Base (first control terminal, second control terminal) C: Collector, (one of the first main terminals, one of the second main terminals), E: Emitter (the other first main terminal, the other second main terminal)

Claims

1. A water heater with a switching valve that can supply a heat medium to a plurality of heat dissipation terminals having a terminal flow path through which the heat medium flows, and is configured to control the switching valve to switch between a first state that permits the supply of the heat medium to the terminal flow path and a second state that shuts off the supply, A hot water supply circuit that heats water supplied from the outside to supply hot water, A burner that burns gas, a heat exchanger that is heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path, and a heating circuit configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger, A control board communicably connected to a plurality of remote controls corresponding to the plurality of heat dissipation terminals, The control board includes a control device having a plurality of connection terminals and a switching circuit capable of switching the remote control in a communication state with the control device, The switching circuit includes a remote control side connection portion electrically connected to each remote control, a control device side connection portion electrically connected to each connection terminal, a plurality of first transistors each having a first control terminal and a pair of first main terminals, and a plurality of second transistors each having a second control terminal and a pair of second main terminals, The plurality of control device side connection portions have a plurality of first ports and a plurality of second ports, The plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports, One of the pair of first main terminals in the first transistor is electrically connected to the remote control side connection portion, and the other is electrically connected to the input / output terminal, One of the pair of second main terminals in the second transistor is electrically connected to the first control terminal, the other is electrically connected to one of the first ports, and the second control terminal is electrically connected to one of the second ports, By the combination of the switching signals applied to each of the first ports and each of the second ports, the remote control side connection portion communicably connected to the input / output terminal is selected and switched from among the plurality of remote control side connection portions, Water heater.

2. A water heater is configured to supply the heat medium to a plurality of heat dissipation terminals having terminal flow paths through which the heat medium flows, and controls a switching valve that switches between a first state in which the supply of the heat medium to the terminal flow path is permitted and a second state in which the supply is blocked. A hot water supply circuit that heats water supplied from the outside to supply hot water. A burner that burns gas, a heat exchanger that is heated by the exhaust gas generated by the combustion of the gas in the burner, and a heat medium circulation path that is a path for circulating the heat medium together with the terminal flow path. The heating circuit is configured such that the heat medium flowing through the heat medium circulation path is heated by the heat exchanger. A control board connected to a plurality of remote controls corresponding to the plurality of heat dissipation terminals via communication means. Comprising The control board includes a control device having a plurality of connection terminals, and a switching circuit capable of switching the remote control in a communication state with the control device. The switching circuit includes a remote control side connection part electrically connected to each remote control, a control device side connection part electrically connected to each connection terminal, and a plurality of transistors. The plurality of control device side connection parts have a plurality of first ports and a plurality of second ports. The plurality of connection terminals in the control device include input / output terminals for inputting or outputting information to and from the remote control, and a plurality of switching terminals for outputting a switching signal composed of a high-level signal or a low-level signal to the plurality of first ports and the plurality of second ports. The sum of the number of the plurality of first ports and the number of the plurality of second ports is less than the number of the plurality of remote control side connection parts. The switching circuit switches so as to select a remote control side connection part communicably connected to the input / output terminal from among the plurality of remote control side connection parts according to a combination of the switching signals given to each of the first ports and each of the second ports. Water heater.

3. A first transistor which is an NPN-type bipolar transistor. A second transistor which is a PNP-type bipolar transistor. Comprising The sum of the number of the plurality of first ports and the number of the plurality of second ports is less than the number of the plurality of remote control side connection parts. A plurality of sets of the second transistor and the first transistor are configured such that the collector of each of the second transistors is electrically connected to the base of each of the first transistors, and the collector of the first transistor of each set is electrically connected to each of the remote control side connection portions, the emitter of the first transistor of each set is electrically connected to the input / output terminal, the emitter of the second transistor of each set is electrically connected to the first port, the emitter of the second transistor of each set is assigned to any one of the first ports such that the emitters of a plurality of the second transistors are electrically connected to each of the first ports, the base of the second transistor of each set is assigned to any one of the second ports such that the bases of a plurality of the second transistors are connected to each of the second ports, the first transistor and the second transistor of the set in which a high-level voltage is applied to the emitter of the second transistor and a low-level voltage is applied to the base of the second transistor are turned on, the first transistor and the second transistor of the set in which at least either a low-level voltage is applied to the emitter of the second transistor or a high-level voltage is applied to the base of the second transistor are turned off, communication becomes possible between the remote control side connection portion to which the collector of the first transistor of the set in which the first transistor and the second transistor are turned on is electrically connected and the input / output terminal The water heater and warmer according to claim 1 or claim 2.

4. The control device switches the combination of the switching signals given to the plurality of first ports and the plurality of second ports so that each of the plurality of remote control side connection portions can communicate with the input / output terminal selectively with a time difference. The water heater and warmer according to claim 1 or claim 2.

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