Hot water heater

Abstract

To provide a hot water heater which can prevent a shortage of output terminals of a control device while suppressing inrush current of a circuit.SOLUTION: A hot water heater 1 has a heating circuit 3. The heating circuit 3 includes: a hot water supply circuit 2 which heats water supplied from the outside to supply hot water; a heating burner 33A which burns a gas; a heater side heat exchanger 32 which is heated by exhaust air generated by the gas burning in the heating burner 33A; a heat medium circulation passage 48 serving as a path for circulating a heat medium with a second terminal passage 38H; and a heating circulation pump 37 which causes the heat medium to circulate in the heat medium circulation passage 48. Further, the hot water heater 1 includes: a current suppression element 93 which suppresses inrush current; a relay 91 connected in parallel with the current suppression element 93; a control device 70 which controls driving of the heating circulation pump 37; and a switching unit which switches the relay 91A into an off state in conduction with driving of the heating circulation pump 37.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes an electric water heater. This electric water heater includes a power switch connected to a commercial power supply, a rectifying and smoothing circuit connected to the power switch via a current limiting element, a relay contact connected in parallel with the current limiting element, and a control means connected to the rectifying and smoothing circuit. The relay contact is opened and closed by a signal from the control means. When the power switch is turned on, the current limiting element is energized, and the relay is turned on after a predetermined time from when it is energized. In this electric water heater, immediately after the power switch is turned on, the inrush current is suppressed by the current limiting element, and then, as current flows through the relay, the power consumption is reduced.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electric water heater disclosed in Patent Document 1, after suppressing the inrush current by the current limiting element, the control means turns on the relay to bypass the current through the relay. In this electric water heater, when a control device such as a microcomputer is used as the control means, it is necessary to allocate a terminal of the control device (for example, an output terminal of the microcomputer) for driving the relay in order to turn the relay on and off.

[0005] Such a technique (a technique in which a relay is connected in parallel to a current limiting element and a control device switches an energization path by turning the relay on and off) can also be applied to a water heater. However, in a water heater, many connection targets (for example, detectors, actuators, etc.) are likely to be connected to each terminal of the control device, and it is difficult to secure a large number of independent control structures. For example, this type of water heater has a problem that the terminals of the control device (for example, the output terminals of the microcomputer) are likely to be insufficient. If terminals are allocated for turning the relay for the bypass on and off, the problem of insufficient number of terminals will become more prominent.

[0006] One of the objects of the present disclosure is to realize a configuration that can achieve both suppression of inrush current immediately after the start of energization and suppression of normal loss while aiming for commonality of the control structure.

Means for Solving the Problems

[0007] A water heater according to one aspect of the present disclosure is configured to be able to supply the heat medium to a heat dissipation terminal having a terminal flow path through which the heat medium flows, and controls a switching valve that switches between a first state that permits supply of the heat medium to the terminal flow path and a second state that blocks it. The water heater is a hot water supply circuit that heats water supplied from the outside to supply hot water, a burner that burns gas, a first 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 first heat exchanger, a pump that causes a fluid to flow, a current suppression element that is arranged in a power path that is a path for supplying power from a power source and suppresses an inrush current flowing through the power path, a relay connected in parallel to the current suppression element, a control device that controls the driving of the pump and switches between a state in which a driving signal for driving the pump is output and a state in which the output of the driving signal is stopped. A drive unit that supplies driving power to the pump based on the power from the power path when the drive signal is output from the control device, and stops supplying driving power to the pump when the drive signal is not output; A switching unit that switches the on / off state of the relay; and is provided with; When the relay is in the on state, one end side and the other end side of the current suppression element are in a conductive state where they are conducted through the relay, and when the relay is in the off state, the conductive state is released; The drive unit is configured such that the voltage at a predetermined part switches when changing from a state of stopping the supply of the drive power to a state of supplying the drive power; The switching unit is electrically connected to the predetermined part, turns off the relay according to the voltage at the predetermined part before the start of driving of the pump, and switches the relay to the on state in conjunction with the switching of the voltage at the predetermined part accompanying the start of driving of the pump.

Advantages of the Invention

[0008] The technology according to the present disclosure can suppress the inrush current of the circuit and suppress the shortage of the number of output terminals of the control device.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0010] Each of the following [1] to [4] is an example of a hot water supply and heating machine or a hot water supply and heating system included in the present disclosure.

[0011] A water heater and heater that is configured to supply the heat medium to a heat dissipation terminal having a terminal flow path through which the heat medium flows, and controls a switching valve that switches between a first state that permits 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 first 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 first heat exchanger, A pump that causes a fluid to flow, A current suppression element that is arranged in a power path that is a path for supplying power from a power source and suppresses an inrush current flowing through the power path, A relay connected in parallel to the current suppression element, A control device that controls the driving of the pump and switches between a state in which a driving signal for driving the pump is output and a state in which the output of the driving signal is stopped, A driving unit that supplies driving power to the pump based on the power from the power path when the driving signal is output from the control device, and stops the supply of driving power to the pump when the driving signal is not output, A switching unit that switches the on / off state of the relay, and is provided with When the relay is in the on state, a conductive state is established in which one end side and the other end side of the current suppression element are conducted through the relay, and when the relay is in the off state, a released state is established in which the conductive state is released, The driving unit is configured such that the voltage at a predetermined part switches when changing from a state in which the supply of the driving power is stopped to a state in which the driving power is supplied, The switching unit is electrically connected to the predetermined part, turns off the relay according to the voltage at the predetermined part before the start of driving of the pump, and switches the relay to the on state in conjunction with the switching of the voltage at the predetermined part accompanying the start of driving of the pump Water heater and heater.

[0012] Before the start of driving the pump, the water heater described in [1] turns off the relay according to the voltage at a predetermined part of the driving unit. Therefore, before the start of driving the pump, the ratio of the current flowing through the current suppression element among the currents flowing through the power path can be increased. Thus, for example, even if an inrush current flows through the power path immediately after it is switched from a state where it is not connected to an external power source to a connected state, it is possible to suppress a large inrush current from flowing through the current suppression element. On the other hand, when the control device outputs a drive signal to drive the pump, the drive unit supplies drive power to the pump, and the voltage at a predetermined part of the drive unit changes. The switching unit switches the relay to the on state in conjunction with the change in the voltage at the predetermined part accompanying the start of driving the pump. Therefore, after the start of driving the pump, more current can flow through the relay. Thus, the water heater can suppress the current flowing through the current suppression element during the driving of the pump, suppress a large loss in the current suppression element, and suppress an increase in power consumption. Further, since the switching unit is electrically connected to a predetermined part of the drive unit and operates to switch the relay to the on state in conjunction with the change in the voltage at the predetermined part accompanying the start of driving the pump, this water heater can switch the relay to the on state in conjunction with the driving of the pump without securing a dedicated terminal for relay switching in the control device. Therefore, this water heater can suppress the inrush current of the circuit and suppress the shortage of the output terminal number of the control device. Moreover, since the water heater can switch the relay to the on state according to the driving period of the pump during which the consumption current increases more, it can effectively suppress the power consumption during the period when heat generation is more concerned (the driving period of the pump).

[0013] 〔2〕 A bath circuit having a bath circulation path for circulating the hot water derived from the bathtub and returning it to the bathtub, and a second heat exchanger for heating the hot water flowing through the bath circulation path As the pump, a heating circulation pump for flowing the heat medium in the heat medium circulation path and a bath circulation pump for flowing the hot water in the bath circulation path are provided. When both the heating circulation pump and the bath circulation pump are stopped, the switching unit maintains the relay in the off state, and when any one of the drives starts from the state where both the heating circulation pump and the bath circulation pump are stopped, the relay is switched to the on state in conjunction with the start of any one of the drives. The water heater according to [1].

[0014] The water heater of [2] above can maintain the relay in the on state when both the heating circulation pump and the bath circulation pump are stopped, so it can maintain the function of suppressing the inrush current during the stop of the pump. On the other hand, the water heater can switch the relay to the on state in accordance with the start of the drive of either the heating circulation pump or the bath circulation pump, so no matter which pump causes the increase in the consumed current, the current flowing through the current suppression element can be suppressed, and the heat generation can be suppressed.

[0015] 〔3〕The current suppression element is mounted on a substrate, and at least a potting material covering the current suppression element is stacked on the substrate. The water heater according to [1] or [2].

[0016] The water heater of [3] above can enjoy the advantages of the potting material, but there is a concern that the heat generated by the current suppression element may affect the potting material. Especially when the pump with an increased consumed current is driven, this problem is more concerning. However, the water heater can conduct the relay in accordance with the drive of the pump to suppress the energization of the current suppression element, so the influence of heat generation on the potting material can be effectively suppressed.

[0017] 〔4〕A water heating and heating system including the heat dissipation terminal and the water heater according to any one of [1] to [3].

[0018] <First Embodiment> The following description relates to the water heater 1 according to the first embodiment. 1. Overall Configuration of the Water 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 bathtub circuit 4, etc., and is a device capable of performing hot water supply operations, automatic water filling operations, reheating operations, heating operations, etc.

[0019] The water heater and heater 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 the hot water supply burner 8A, the heating burner 33A, the hot water supply side heat exchanger 7, the heating side heat exchanger 32, etc. 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 heating operations or reheating operations.

[0020] The hot water supply circuit 2 is a circuit that heats water supplied from outside the water heater and heater 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 the 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 control device 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 in the hot water supply combustion chamber 5A. The hot water supply side burner unit 8 includes burner blocks 9A, 9B, 9C, and each of the burner blocks 9A, 9B, 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.

[0021] 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 pipe 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 pipe 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.

[0022] 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), and the like. 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 pipe 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 pipe 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.

[0023] 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 water flowing through the bypass pipe 12. Specifically, it is configured as a valve that changes the opening degree of the bypass pipe 12 by control. A thermistor 15A is provided upstream 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. Specifically, it 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 downstream 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. Specifically, it detects the temperature of the hot water supplied downstream 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 control device 70 described later.

[0024] 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 outside 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 upstream of the gas pipe 16, and a gas proportional valve 18 is provided downstream 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. Solenoid valves 19 are respectively provided in each of the branch pipes 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 (shut-off state), and the supply and shut-off of 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.

[0025] 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 control device 70. The hot water supply circuit 2 is also provided with an igniter for ignition, an ignition electrode, a hot water supply frame rod, and the like.

[0026] 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.

[0027] The bathtub heat exchanger 50 is provided with a pipe 50A that forms part of the bathtub circulation path 63, and the bathtub heating pipe 51 is arranged inside 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 operates, the bathtub circulation path 63 functions as a flow path for drawing out hot water from the bathtub 52 provided outside the water heater 1, and 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 in the bathtub return pipe 54 in a predetermined direction, and a water flow switch 57 for detecting that hot water with 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 operates. 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 operates. 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 to 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.

[0028] 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, etc. When the hot water supply solenoid valve 60 provided in the drain pipe 59 is in an open state 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.

[0029] The heating circuit 3 is a circuit that can heat the heat medium by means of 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. The heat medium circulation path 48 is a path for circulating the heat medium together with the first terminal flow path 38G (terminal flow path) and the second terminal flow path 38H (terminal flow path). In the present embodiment, the heat medium is, for example, hot water. Note that, as the heat medium, a fluid other than hot water may be used. The heating circuit 3 includes the second combustion system unit 6 and the 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.

[0030] 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. 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.

[0031] The heating-side heat exchanger 32 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 section 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 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.

[0032] 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.

[0033] When the first heat dissipation terminal 39A as a heating terminal is connected as shown in FIG. 1, the heat medium circulation path 48 is configured such that the heat medium circulates 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 such that the heat medium circulates 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.

[0034] 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 hot water heater 1. The first internal flow path 38A is configured as a flow path branching 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 first heat exchanger 32A on the heating side, and the heat medium flowing through the first internal flow path 38A is configured to be heated in the first heat exchanger 32A on the heating side.

[0035] 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 hot water heater 1. The second internal flow path 38B is configured as a flow path branching 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.

[0036] The heating circuit 3 further includes an expansion tank 36, a heating circulation pump 37, 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 and the heat medium exiting from 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.

[0037] 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 formed 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.

[0038] 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.

[0039] The second internal flow path 38B is provided in a configuration where a plurality of internal branch paths 38F branch off. A 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 dissipation terminal 39Z and is connected to the second heat dissipation terminal 39Z outside the appliance. The downstream sides of the first heat dissipation terminal 39A and the second heat dissipation terminal 39Z communicate with a common return flow path 38C. The first heat dissipation terminal 39A is, for example, a high-temperature heating terminal such as a heating blower that blows warm air into a bathroom or a dressing room. The second heat dissipation terminal 39Z is, for example, a low-temperature heating terminal such as floor heating in a dressing room.

[0040] 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 heat exchanger 32A on the heating side). The temperature detected by the heating high-temperature thermistor 40 corresponds to the temperature of the heat medium flowing into the first heat dissipation terminal 39A during the circulation of the heat medium passing through the first heat dissipation 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 dissipation terminal 39Z during the circulation of the heat medium passing through the second heat dissipation terminal 39Z.

[0041] 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 stage number. Note that the heating circuit 3 is also provided with an ignition electrode, a heating frame rod, and the like.

[0042] 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 switching valve 39G, which is a thermostatic valve inside the appliance.

[0043] 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 downstream of the heating-side heat exchanger 32 in the heat medium circulation path 48 (specifically, downstream 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.

[0044] The control valve 58 is a valve provided upstream 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 where it outputs a predetermined first signal (for example, an on signal), and when the control valve 58 is in the fully closed state where it is blocked, it enters a second state where it outputs a second signal (for example, an off signal) different from the first signal.

[0045] The hot water supply and heating machine 1 further includes a control device 70, a hot water supply remote controller 71, a bath remote controller 72, a heating remote controller 73, and a room temperature thermistor (not shown). The control device 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 control device 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, for example, in the dressing room as a means for detecting the temperature in the dressing room. Note that the control device 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.

[0046] 2. Basic operation of the hot water supply and heating machine 1 (Normal hot water supply operation) When a hot water supply faucet provided outside the apparatus to communicate with the hot water outlet pipe 10 is opened and water flows into the apparatus, and the water volume sensor 14 outputs a signal indicating the flow of water, the control device 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 control device 70 opens the main 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, and controls to supply 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 out to the hot water outlet pipe 10, and the hot water is discharged from the hot water supply faucet.

[0047] During the above hot water discharging operation, the control device 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 becomes the set temperature indicated by the hot water supply remote control 71 or the bath remote control 72. At the same time, the air volume is continuously changed by controlling the rotation speed of the fan 20. When the hot water supply faucet is closed during the above-mentioned hot water discharging operation and the signal output by the water volume sensor 14 becomes a signal indicating a water flow stop state, the control device 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.

[0048] (Automatic hot water filling operation) The control device 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 control 71 or the bath remote control 72 is pressed, the control device 70 sets the hot water temperature to the hot water filling temperature set by the hot water supply remote control 71 or the bath remote control 72 as the target temperature (for example, 40 ° C) and starts hot water filling. Specifically, the control device 70 opens the hot water supply solenoid valve 60 in the dropping pipe 59 to put 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.

[0049] After starting the supply of hot water to the bathtub 52 in this way, the control device 70 monitors whether the water volume (total water volume since the start of automatic hot water filling) detected by the dropping water volume sensor 61 provided in the dropping pipe 59 has reached the set water volume. When it is confirmed that the water volume has reached the set water volume, the control device 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 control device 70 operates the bath circulation pump 55 to circulate the hot water in the bathtub 52 in the bath circuit 4. When the control device 70 finishes the hot water filling, it notifies the hot water supply remote control 71 or the bath remote control 72 of the end of the hot water filling.

[0050] (Automatic reheating operation) The control device 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 control 71 or the bath remote control 72 is pressed, the control device 70 sets the reheat temperature to the target temperature (e.g., 40°C) set on the hot water supply remote control 71 or the bath remote control 72 and starts the reheat. Specifically, the control device 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 control device 70 monitors whether the hot water temperature detected by the bath return thermistor 65 has reached the target temperature. When it is confirmed that the target temperature has been reached, the control device 70 extinguishes the heating burner 33A, stops the bath circulation pump 55, and ends the reheat. When the control device 70 ends the reheat, it notifies the hot water supply remote control 71 or the bath remote control 72 of the end of the reheat.

[0051] 3. Configuration for supplying a heat medium to the first heat dissipation terminal 39A (high-temperature heating terminal) and the second heat dissipation terminal 39Z (low-temperature heating terminal) 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 that has been branched and diverted through an internal flow path to the external first heat dissipation terminal 39A and second heat dissipation terminal 39Z.

[0052] 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 diverts 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. 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 a bypass flow path 46.

[0053] 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.

[0054] The downstream end of the first internal flow path 38A is configured as a first outflow portion 35B that can be connected to the outside and 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 as a second outflow portion 35C that can be connected to the outside and 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 as an inflow portion 35A that can be connected to the outside and through which the heat medium flows in. The inflow portion 35A is provided on the downstream side of the first terminal flow path 38G and on the downstream side of the second terminal flow path 38H, and is an inlet through which the heat medium that has flowed through the first terminal flow path 38G flows in, and is also an inlet through which the heat medium that has flowed through the second terminal flow path 38H flows in.

[0055] Outside the hot water heater 1, a first heat dissipation terminal 39A and a second heat dissipation terminal 39Z are provided, to which the heat medium is supplied from the hot water heater 1 and which communicate with the heat medium circulation path 48. 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 connectable so as to communicate with the inflow portion 35A of the hot water heater 1.

[0056] 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 opening and closing the high-temperature switching valve 39H. When the high-temperature switching valve 39H is open, it is allowed for the heat medium to pass through the high-temperature switching valve 39H, and it is allowed 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 (inflow portion 35A side) of the high-temperature switching valve 39H. When the high-temperature switching valve 39H is closed, 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 (second state) and a state where the supply of the heat medium is permitted (first state) by opening and closing the switching valve 39G. When the switching valve 39G is open (first state), it is allowed for the heat medium to pass through the switching valve 39G, and it is allowed 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 (inflow portion 35A side) of the switching valve 39G. When the switching valve 39G is closed (second state), it is blocked for the heat medium to pass through the 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 switching valve 39G. Both the high-temperature switching valve 39H and the switching valve 39G are thermal valves. The thermal valve, for example, expands an expansion body with the heat of a heating element (Positive Temperature Coefficient) when the power is on to push a piston to open the valve so that hot water flows, and when the power is off, the heating element naturally dissipates heat to contract the expansion body to close the valve.

[0057] The heat medium flowing into the inflow portion 35A circulates through the heat medium circulation path 48 in 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 further moves downstream by the power of the heating circulation pump 37. Then, the heat medium flowing toward the branch portion 38J is divided at the branch portion 38J into the heat medium flowing toward the first internal flow path 38A and the heat medium flowing 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.

[0058] 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 the outlet. The heat medium flowing through the second internal flow path 38B flows out toward the second terminal flow path 38H with the second outflow portion 35C as the outlet.

[0059] The high-temperature switching valve 39H that opens and closes the first terminal flow path 38G, the switching valve 39G that opens and closes the second internal flow path 38B, and the heating circulation pump 37 are controlled by the control device 70. The control device 70 is electrically connected to each of the high-temperature switching valve 39H, the switching valve 39G, and the heating circulation pump 37, and performs opening / closing control of the high-temperature switching valve 39H and the switching valve 39G and drive control of the heating circulation pump 37.

[0060] 4. Bypass configuration FIG. 2 is a diagram schematically showing the circuit configuration of the water heater 1. The water heater 1 includes an AC load circuit 87, a rectifying and smoothing circuit 88, a current suppression element 93, a diode bridge circuit 89, and a smoothing capacitor 94 between the first power lines LA and LB connected to a power source P such as a commercial power source outside the water heater 1.

[0061] The AC load circuit 87 is supplied with power from a power source P such as a commercial power source and supplies power to the AC load of the water heater 1. The AC load circuit 87 supplies power to loads driven by alternating current such as opening / closing of each switching valve 39G and a freeze prevention heater, for example.

[0062] The rectifying and smoothing circuit 88 receives the output of the AC load circuit 87, has a function as a noise filter, and removes noise from the AC output from the AC load circuit 87.

[0063] The current suppression element 93 is, for example, an NTC (Negative Temperature Coefficient) thermistor, has a large resistance at the start of energization, and has a decreasing resistance as the temperature rises after the start of energization. Since the resistance of the current suppression element 93 is large at the start of energization, the inrush current of the circuit can be suppressed.

[0064] The current suppression element 93 is connected in parallel with a relay 91 configured as a bypass relay. The relay 91 is, for example, a normally open relay that is in an off state when not energized, and includes a relay contact 91A and a relay coil 91B. The relay contact 91A is connected in parallel with the current suppression element 93. When the relay coil 91B is energized, the relay contact 91A becomes in an on state (energized state), and when the relay contact 91A closes, the current flowing through the relay contact 91A becomes significantly larger than the current flowing through the current suppression element 93, and most of the current flowing through the first power path LA is bypassed so as to flow through the relay contact 91A. When the relay coil 91B is not energized, the relay contact 91A becomes in an off state (energization cut-off state), and when the relay contact 91A opens, no current flows through the relay contact 91A, and most (all in a representative example) of the current flowing through the first power path LA flows through the current suppression element 93. The relay coil 91B is configured to be de-energized in conjunction with the driving of the heating circulation pump 37, and the specific operation of the conjunction will be described later.

[0065] The diode bridge circuit 89 rectifies the outputs of the rectifying and smoothing circuit 88 and the current suppression element 93. The smoothing capacitor 94 is a capacitor that smoothes the output of the diode bridge circuit 89. One electrode of the smoothing capacitor 94 is electrically connected to the first power path LA, which is one of a pair of power paths (the first power paths LA and LB), and the other electrode is electrically connected to the first power path LB, which is the other of the pair of power paths. For example, when a pair of power paths (the first power paths LA and LB) are connected to a power source P such as a commercial power source in a state where the smoothing capacitor 94 in the hot water heating machine 1 is not charged, an inrush current is generated immediately after the connection when the smoothing capacitor 94 is charged.

[0066] FIG. 3 shows a circuit that switches relay 91 in conjunction with the drive of heating circulation pump 37. The drive circuit 96 shown in FIG. 3 corresponds to an example of a drive unit and is a circuit that supplies a predetermined voltage (for example, 15 [V]) based on the power supplied from power source P (for example, 100V AC power) to conductive path L2. Conductive path L2 is wiring constituted by a conductor. Drive circuit 96 may be configured to be able to generate a DC voltage of the predetermined voltage and supply the DC voltage of the predetermined voltage to pump 37 when receiving a drive signal from control device 70, and stop the supply of the DC voltage when not receiving the drive signal. Alternatively, drive circuit 96 may be configured to be able to supply a predetermined DC voltage from a power supply circuit configured as a circuit separate from drive circuit 96 to conductive path L2, energize the power supply circuit and conductive path L2 to supply the DC voltage to pump 37 when receiving a drive signal from control device 70, and cut off the energization between the power supply circuit and conductive path L2 to stop the supply of the DC voltage when not receiving the drive signal.

[0067] Conductive path L3 is wiring constituted by a conductor, is short-circuited to conductive path L2 so as to branch from conductive path L2, and is configured to have the same potential as conductive path L3. Conductive path L3 is wiring provided to operate relay 91 in conjunction with heating circulation pump 37, and relay coil 91B is electrically connected to conductive path L3. In the configuration of FIG. 3, when drive circuit 96 operates and a DC voltage is applied to conductive path L2, current flows through relay coil 91B via conductive path L3, and relay contact 91A of relay 91 turns on to close. In the example of FIG. 3, conductive path L3 and relay coil 91B are an example of a switching unit.

[0068] The conductive path L4 is electrically connected to one end side of the heating circulation pump 37, and the other end side of the heating circulation pump 37 is grounded. The conductive path L4 is a wiring constituted by a conductor and is electrically connected to the conductive path L2 so as to be short-circuited to the conductive path L2. In the example of FIG. 3, when a DC voltage is applied to the conductive path L4, a current flows from the conductive path L4 to the ground side through the heating circulation pump 37, and the heating circulation pump 37 operates by such energization. In the water heater 1 of FIG. 1, due to the operation of the heating circulation pump 37, the heat medium in the heat medium circulation path 48 circulates through the heat medium circulation path 48.

[0069] 5. Operation during heating When the power supply P such as a commercial power supply is not connected to the water heater 1 and the smoothing capacitor 94 is not fully charged (for example, in a fully discharged state), the driving of the heating circulation pump 37 and the bath circulation pump 55 is stopped, and since the conductive paths L2 and L3 are in a state where no DC voltage is applied (for example, 0 V), the relay 91 is in an off state. In such a state, when the water heater 1 is connected to the power supply P and switched from a state where no power is supplied from the power supply P to the water heater 1 to a state where power is supplied, based on the power supply from the power supply P, the power supply to the first power paths LA and LB is started, and the AC load circuit 87, the rectifying and smoothing circuit 88, the current suppressing element 93, and the diode bridge circuit 89 are energized, and the smoothing capacitor 94 is charged. At the start of this energization (the point immediately before switching from the state where the power supply to the first power paths LA and LB is stopped to the state where the power supply is started), since the relay 91 is in the off state, most of the inrush current flowing through the first power path LA with the start of energization (in a representative example, all of the current flowing from one end side to the other end side of the current suppressing element 93) flows through the current suppressing element 93, and the smoothing capacitor 94 is charged.

[0070] After the power supply P is connected to the water heater 1 and the smoothing capacitor 94 is charged in this way, when the driving start condition of the heating circulation pump 37 is satisfied with the power supply P connected to the water heater 1 (for example, when an operation to start heating such as floor heating is performed from the heating remote controller 73 or the like), the control device 70 gives a driving signal to the driving circuit 96. The driving circuit 96 does not apply a driving voltage (DC voltage) to the conduction path L2 when no driving signal is given from the control device 70, and applies a driving voltage (DC voltage) to the conduction path L2 when a driving signal is given from the control device 70. Then, the conduction path L2 is set to a predetermined low potential (for example, 0V) when no driving voltage is given from the driving circuit 96, and when a driving voltage is given from the driving circuit 96 to the conduction path L2 (when power is supplied from the driving circuit 96 to the conduction path L2), the power from the driving circuit 96 is supplied to the heating circulation pump 37 via the conduction path L4, and the heating circulation pump 37 is driven. When the driving start condition of the heating circulation pump 37 is satisfied (for example, when an operation to start heating such as floor heating is performed from the heating remote controller 73 or the like), various operations for performing the heating operation are also performed in addition to the heating circulation pump 37. For example, the control device 70 controls the switching valve corresponding to the heating terminal to be driven among the high-temperature switching valve 39H and the switching valve 39G to open, and also controls the combustion of the heating burner 33A.

[0071] Furthermore, when a drive voltage (DC voltage) is applied to the conduction path L2 by the control device 70 supplying a drive signal to the drive circuit 96, and the relay coil 91B is energized via the conduction path L3, the relay contact 91A of the relay 91 closes and becomes in an on state, and a bypass current flows through the relay 91 (specifically, the relay contact 91A). When such a bypass current flows through the relay 91, since the resistance of the relay 91 is significantly lower than that of the current suppression element 93 (for example, a thermistor or other resistance element), almost no current flows through the current suppression element 93. In this specification, a portion (such as a terminal short-circuited to the conduction path L2) electrically connected to the conduction path L2 in the drive circuit 96 corresponds to an example of a predetermined portion. Thus, the drive circuit 96 is configured such that the voltage of the predetermined portion switches when changing from a state of stopping the supply of drive power to the heating circulation pump 37 to a state of supplying drive power. Note that in a state where the control device 70 is not supplying a drive signal to the drive circuit 96, that is, in a state where the drive circuit 96 has stopped supplying drive power to the heating circulation pump 37, no current flows through the relay coil 91B, and the relay contact 91A of the relay 91 is maintained in an open off state.

[0072] When the drive stop condition of the heating circulation pump 37 is satisfied (for example, when an operation to stop heating such as floor heating is performed from the heating remote controller 73 or the like), the control device 70 stops the drive signal being supplied to the drive circuit 96. When the drive signal stops, the drive circuit 96 stops applying a DC voltage to the conduction path L2 during the stop of the drive signal. Thus, when the control device 70 stops the drive signal, the energization of the conduction paths L2, L3, and L4 is interrupted, power is no longer supplied to the heating circulation pump 37, and the drive of the heating circulation pump 37 stops. Then, the relay coil 91B connected to the conduction path L3 becomes in a non-energized state, and the relay contact 91A of the relay 91 becomes in an off state so as to open. Therefore, the relay 91 becomes in an off state (the relay contact 91A is in a current interruption state), and the current flowing through the first power path LA flows through the current suppression element 93 without bypassing the relay 91.

[0073] 6. Examples of effects Before the pump starts driving, the hot water heating unit 1 turns off the relay 91 according to the voltage at a predetermined part of the drive circuit 96. Therefore, before the pump starts driving, the ratio of the current flowing through the current suppression element 93 in the current flowing through the first power path LA can be increased. Thus, for example, even if an inrush current flows through the first power path LA immediately after it is switched from a state where it is not connected to an external power source to a connected state, the current suppression element 93 can suppress the flow of a large inrush current. On the other hand, when the control device 70 outputs a drive signal to drive the pump, the drive circuit 96 supplies drive power to the pump, and the voltage at a predetermined part of the drive circuit 96 changes. The switching unit switches the relay 91 to the on state in conjunction with the change in the voltage at a predetermined part accompanying the start of driving of the pump. Therefore, after the pump starts driving, more current can flow through the relay 91. Thus, the hot water heating unit 1 can suppress the current flowing through the current suppression element 93 during the driving of the pump, and can suppress an increase in power consumption caused by a large loss occurring in the current suppression element 93.

[0074] Furthermore, since the switching unit is electrically connected to a predetermined part of the drive circuit 96 and operates to switch the relay 91 to the on state in conjunction with the change in the voltage at a predetermined part accompanying the start of driving of the pump, this hot water heating unit 1 can switch the relay 91 to the on state in conjunction with the driving of the pump without securing a dedicated terminal for relay switching in the control device 70. Thus, this hot water heating unit 1 can suppress the shortage of the output terminal number of the control device 70 while suppressing the inrush current of the circuit. Moreover, since the hot water heating unit 1 can switch the relay 91 to the on state in accordance with the driving period of the pump when the consumption current increases more, it can effectively suppress the power consumption during the period when heat generation is more concerning (the driving period of the pump).

[0075] When both the heating circulation pump and the bath circulation pump of the water heater 1 are stopped, the relay 91 can be maintained in the ON state, so that the function of suppressing the inrush current can be maintained during the stop of the pumps. On the other hand, when the drive of either the heating circulation pump or the bath circulation pump of the water heater 1 starts, the relay 91 can be switched to the ON state in accordance with the start of the drive of the pump. Therefore, even when the current consumption increases due to either pump, the current flowing through the current suppression element can be suppressed to suppress heat generation.

[0076] While the water heater 1 can enjoy the advantages of the potting material, there is concern that the heat generation in the current suppression element 93 may affect the potting material, and this problem is even more concerning especially when the pump with increased current consumption is driven. However, since the water heater 1 can conduct the relay 91 in accordance with the drive of the pump to suppress the energization of the current suppression element 93, the influence of heat generation on the potting material can be effectively suppressed.

[0077] <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 below-described embodiments can be combined in any non-contradictory range. Also, any feature of the above-described or below-described embodiments can be omitted if it is not explicitly stated as essential. Furthermore, the above-described embodiments may be modified as follows.

[0078] In the above-described embodiment, the relay 91 is turned off in conjunction with the drive of the heating circulation pump 37, but the present invention is not limited to this configuration. For example, the relay 91 may be turned off in conjunction with the drive of the bath circulation pump 55. Alternatively, when power is supplied to either the heating circulation pump 37 or the bath circulation pump 55, the relay 91 may be turned off in conjunction with this.

[0079] In the above-described embodiment, the relays 91 and the common relay 92 are typically mechanical relays that operate by energizing a coil, but the configuration is not limited thereto. For example, the relays 91 and the common relay 92 may be constituted by semiconductor switching elements such as transistors.

[0080] In the above-described embodiment, the portion (such as a terminal short-circuiting to the conductive path L2) electrically connected to the conductive path L2 in the drive circuit 96 corresponds to an example of a predetermined portion, but the example is not limited thereto. Any portion where the voltage switches between a state where the supply of drive power to the heating circulation pump 37 is stopped and a state where the drive power is supplied in the drive circuit 96 may be used as the predetermined portion (for example, a portion that is not a portion short-circuiting to the conductive path L2).

[0081] The method of supplying power to the first power paths LA and LB is not limited to the above-described embodiment, and AC power or DC power may be supplied to the first power paths LA and LB.

[0082] It should be considered that 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 to include all modifications within the scope indicated by the claims or within the scope equivalent to the claims.

Explanation of Reference Numerals

[0083] 1: Hot water supply and heating machine 1A: Container 2: Hot water supply circuit 3: Heating circuit 4: Bath circuit 5A: Hot water supply combustion chamber 6A: Heating combustion chamber 7: Hot water supply side heat exchanger 7Z: Fin 8: Hot water supply side burner unit 8A: Hot water supply burner 9A: Burner block 9B: Burner block 9C: Burner block 10: Hot water outlet pipe 11: Water supply pipe 20: Fan 20A: Driving source 20B: Rotating body 32: Heating-side heat exchanger (first heat exchanger) 32A: Heating-side first heat exchanger 32B: Heating-side second heat exchanger 33: Heating-side burner unit 33A: Heating burner (burner) 34A: Burner block 34B: Burner block 35A: Inflow section 35B: First outflow section 35C: Second outflow section 36: Expansion tank 36C: Inlet section 36B: Outlet section 37: Heating circulation pump (pump) 38A: First internal flow path 38B: Second internal flow path 38C: Common return flow path 38K: Common forward flow path 38J: Branch section 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 39G: Switching valve 46: Bypass flow path 48: Heat medium circulation path 50: Bath heat exchanger (second heat exchanger) 56: Supplementary heating branch section 70: Control device 76: Driving section 91: Bypass relay 91A: Relay contact 91B: Relay coil (switching section) 92: Common relay 92A: Relay contact 92B: Relay coil 96: Driving circuit (driving section) LA, LB: First power path L2: Conductive path L3: Conductive path (switching section) L4: Pump drive line

Claims

1. A water heater that is configured to supply the heat medium to a heat dissipation terminal 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, comprising: A hot water supply circuit that heats water supplied from the outside and supplies hot water; A burner that burns gas, a first 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, wherein the heat medium flowing through the heat medium circulation path is configured to be heated by the first heat exchanger; a heating circuit; A pump that causes a fluid to flow; A current suppression element that is arranged in a power path that is a path for supplying power from a power source and suppresses an inrush current flowing through the power path; A relay connected in parallel to the current suppression element; A control device that controls the driving of the pump and switches between a state in which a driving signal for driving the pump is output and a state in which the output of the driving signal is stopped; A driving unit that supplies driving power to the pump based on the power from the power path when the driving signal is output from the control device, and stops the supply of the driving power to the pump when the driving signal is not output; A switching unit that switches the on / off state of the relay; And comprising: When the relay is in the on state, a conduction state is formed in which one end side and the other end side of the current suppression element are conducted through the relay, and when the relay is in the off state, a release state is formed in which the conduction state is released; The driving unit is configured such that the voltage at a predetermined part switches when changing from a state in which the supply of the driving power is stopped to a state in which the driving power is supplied; The switching unit is electrically connected to the predetermined part, turns off the relay according to the voltage at the predetermined part before the start of driving of the pump, and switches the relay to the on state in conjunction with the switching of the voltage at the predetermined part accompanying the start of driving of the pump. A water heater.

2. A bath circuit having a bath circulation path that circulates the hot water derived from the bathtub and returns it to the bathtub, and a second heat exchanger that heats the hot water flowing through the bath circulation path; As the pump, a heating circulation pump that causes the heat medium to flow in the heat medium circulation path and a bath circulation pump that causes the hot water to flow in the bath circulation path are provided. When either the heating circulation pump or the bath circulation pump starts driving from a state where both are stopped, the switching unit switches the relay to the off state in conjunction with the start of the driving of either one. The water heater according to claim 1.

3. The current suppression element is mounted on a substrate, and at least a potting material covering the current suppression element is stacked on the substrate. The water heater according to claim 1 or claim 2.

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