Hot water supply heater

Abstract

To detect abnormality in a control valve which adjusts a flow of a heating medium from a heating circuit side to a bath circuit side.SOLUTION: A hot water supply heater includes: a control valve 58 capable of opening / closing a branch passage 51 for bath heating from a fully-open state to a fully-closed state at a predetermined angle; a switch 88 for outputting a first signal when the control valve 58 comes into a fully-open state, and for not outputting the first signal when the control valve 58 is not in a fully-open state; and a control device 70 which controls the opening of the control valve 58 according to the operation state of at least one of a heating circuit 3 and a bath circuit 4, and in which the first signal is inputted from the switch 88. When an operation state has finished, the control device 70 controls so as to perform: first control for outputting a control signal so that the control valve 58 comes into a fully-open state; and first determination for determining that the control valve 58 is normal in the case where the first signal is inputted from the switch 88 according to the first control and for determining that the control valve 58 is abnormal in the case where the first signal is not inputted from the switch 88 according to the first control.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses an example of a water heater. This water heater is provided with a main circulation circuit constituting a water heating unit, a supplementary combustion primary circuit connected in parallel to a part of the main circulation circuit, and a second heating circulation circuit. The supplementary combustion primary circuit includes a supplementary combustion valve constituted by a flow control valve and a heating unit of a supplementary combustion heat exchanger. The secondary side of the supplementary combustion heat exchanger forms a circulating supplementary combustion secondary circuit. The supplementary combustion valve is a flow control valve that is substantially maintained in a closed state by a control device during supplementary combustion stop and is set to a predetermined opening degree by the control device during supplementary combustion. By controlling the opening degree of the supplementary combustion valve, the bath water in the supplementary combustion secondary circuit flowing through the heat absorption part of the supplementary combustion heat exchanger is supplementary combusted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the water heater of Patent Document 1 shares the heat medium between the heating circulation circuit and the supplementary combustion primary circuit, it has the advantage of being able to miniaturize the device. However, when an abnormality such as a failure occurs in the supplementary combustion valve, there is a risk that, despite a signal being output from the control device to close the supplementary combustion valve, it may actually remain open. If such an abnormality is left undetected, there is a concern that problems may occur.

[0005] One object of the present disclosure is to provide a technique that can more easily detect an abnormality in a control valve that regulates the flow of the heat medium from the heating circuit side to the bath circuit side at an earlier stage.

Means for Solving the Problems

[0006] One of the water heaters disclosed herein is equipped with a first burner that burns gas and a first heat exchanger that is heated by the exhaust gas generated by the first burner, and a hot water supply circuit that heats the water supplied from the outside by the first heat exchanger to supply hot water. equipped with a second burner that burns gas, a second heat exchanger that is heated by the exhaust gas generated by the second burner, and a heat medium circulation path that is a path for circulating the heat medium so as to pass through the second heat exchanger, heating the heat medium by the second heat exchanger, and a heating circuit that supplies the heat medium to the heating terminal via the heat medium circulation path. a bathtub circuit having a bathtub circulation path that circulates the hot water derived from an external bathtub and introduces it into the external bathtub. a liquid-liquid heat exchanger that exchanges heat with the hot water flowing through the bathtub circulation path. a branch path that branches from a position on the downstream side of the second heat exchanger in the heat medium circulation path and guides the heat medium that has flowed through the heat medium circulation path to the liquid-liquid heat exchanger side. a control valve that can be opened and closed from a fully open state to a fully closed state. a switch that outputs a first signal when the control valve is in a first state where it is in the fully open state and does not output the first signal when the control valve is in a second state where it is not in the fully open state. a control device that controls the opening and closing of the control valve and monitors the output from the switch. and when the control device operates the heating circuit without operating the bathtub circuit during the heating-only operation, it controls the control valve to the fully closed state, when operating the heating circuit and operating the bathtub circuit during the supplementary heating operation, it controls the control valve to the open state, and when at least the heating-only operation ends, it controls the control valve to the fully open state and makes a first determination as to whether the switch outputs the first signal in the fully open state. Water heater.

Advantages of the Invention

[0007] According to the technology related to the present disclosure, it is easier to detect an abnormality of a control valve that regulates the flow of the heat medium from the heating circuit side to the bathtub circuit side at an earlier stage.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] The following technology is an example of a hot water supply and heating machine or a hot water supply and heating system included in the present disclosure.

[0010] 〔1〕 A first burner that burns gas, and a first heat exchanger heated by the exhaust generated by the first burner, and a hot water supply circuit that heats water supplied from the outside by the first heat exchanger to supply hot water, A second burner that burns gas, a second heat exchanger heated by the exhaust generated by the second burner, and a heat medium circulation path that is a path through which the heat medium circulates through the second heat exchanger, and a heating circuit that heats the heat medium by the second heat exchanger and supplies the heat medium to a heating terminal via the heat medium circulation path, A bathtub circuit having a bathtub circulation path that circulates hot water derived from an external bathtub and introduces it into the external bathtub, A liquid-liquid heat exchanger that exchanges heat with the hot water flowing through the bathtub circulation path, A branch path that branches from a position on the downstream side of the second heat exchanger in the heat medium circulation path and guides the heat medium that has flowed through the heat medium circulation path to the liquid-liquid heat exchanger side, A control valve capable of opening and closing the branch pipe from a fully open state to a fully closed state, A switch that outputs a first signal when the control valve is in the fully open state and does not output the first signal when the control valve is not in the fully open state, A control device that controls the opening and closing of the control valve and monitors the output from the switch, and The control device controls the control valve to the fully closed state during a heating-only operation in which the heating circuit is operated without operating the bath circuit, controls the control valve to an open state during a supplementary heating operation in which the heating circuit is operated and the bath circuit is operated, controls the control valve to the fully open state at least when the heating-only operation ends, and makes a first determination as to whether or not the switch outputs the first signal in the fully open state. A water heater with a heater. In the water heater with a heater according to [1] above, during a heating-only operation in which the heating circuit is operated without operating the bath circuit, the control valve is controlled to the fully closed state, and during a supplementary heating operation in which the heating circuit is operated and the bath circuit is operated, the control valve is controlled to the open state. Due to such control, during the heating-only operation, by setting the control valve to the fully closed state, it is possible to suppress the heated heat medium from flowing into the bath circuit side, and during the supplementary heating operation, by setting the control valve to the open state, it is possible to promote the heated heat medium to flow into the liquid-liquid heat exchanger and perform the supplementary heating operation well. On the premise of such an operation, further, the control device makes a first determination as to whether or not the switch outputs the first signal when the control valve is controlled to the fully open state at least when the heating-only operation ends. By setting the control valve to the fully open state when the heating-only operation ends, it is possible to forcibly output the first signal to the switch, and by determining whether or not the switch outputs the first signal in the fully open state, it is possible to determine whether or not the switch is properly in the fully open state by the control of the fully open state. That is, if the switch does not output the first signal even when the control is in the fully open state, the control valve is abnormal, and the water heater with a heater can confirm such an abnormality at least when the heating-only operation ends, so it is easier to detect the abnormality of the control valve earlier.

[0011] 〔2〕 When in the sole heating operation, the control device controls the control valve to the fully closed state; when in the supplementary heating operation, the control device controls the control valve to the fully open state; when performing a predetermined freeze prevention operation, the control device controls the control valve to an intermediate state where the opening degree is larger than the fully closed state and smaller than the fully open state. Even when any of the sole heating operation, the supplementary heating operation, and the freeze prevention operation ends, the control device sets the control valve to the fully open state and makes the first determination to determine whether the switch outputs the first signal when in the fully open state. The water heating and heating machine according to 〔1〕.

[0012] The water heating and heating device described in 〔2〕 above can confirm whether the switch is normal each time any of the sole heating operation, the supplementary heating operation, and the freeze prevention operation ends. Therefore, it is easier to detect an abnormality of the control valve at an earlier stage.

[0013] 〔3〕 When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, the control device controls the control valve to the fully closed state. The water heating and heating machine according to 〔1〕 or 〔2〕.

[0014] In the water heating and heating machine described in 〔3〕 above, when the switch does not output the first signal when in the fully open state, that is, when the possibility of an abnormality occurring in the control valve increases, there is a risk that the control valve cannot be adjusted properly. Therefore, by attempting to control to the fully closed state in such a case, it is easier to suppress leaving the valve in an unexpected open state.

[0015] 〔4〕 The control device When a predetermined change condition for changing the opening degree of the control valve to an opening degree other than the fully open state is satisfied when at least one of the operation of circulating the heat medium in the heat medium circulation path of the heating circuit and the operation of circulating hot water in the bath circulation path of the bath circuit is being performed, the control device controls the control valve to the fully open state and makes a second determination to determine whether the switch outputs the first signal when in the fully open state. When it is determined in the second determination that the switch outputs the first signal in the fully open state, the opening degree is changed according to the change condition. When it is determined in the second determination that the switch does not output the first signal in the fully open state, the control valve is controlled to the fully closed state. The hot water supply and heating machine according to any one of [1] to [3].

[0016] In the hot water supply and heating machine of [4] above, not only at the end of operation, but also when in the operating state, by forcibly setting it to the fully open state, abnormalities such as failures of the control valve can be detected. Therefore, it is easier to detect abnormalities of the control valve earlier. And when the possibility of an abnormality occurring in the control valve increases during the inspection in the operating state, by attempting to control it to the fully closed state, it becomes easier to suppress leaving it in an unexpected open state.

[0017] 〔5〕 A first temperature sensor that detects the temperature of the hot water flow path towards the external bathtub in the bathtub circulation path, A second temperature sensor that detects the temperature of the hot water return flow path returning from the external bathtub in the bathtub circulation path, and The control device performs a third control to set the control valve to the fully closed state when the bathtub circuit is in the operating state. After performing the third control, when the difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor is equal to or greater than a predetermined temperature difference, it is determined that the control valve is not in the fully closed state. The hot water supply and heating machine according to any one of [1] to [4].

[0018] In the water heater of the above [5], when the control valve is controlled to the fully closed state by the third control when the bath circuit is in the operating state, since the first signal is not output from the switch even when the control valve is in the fully closed state, it is impossible to detect that the control valve is in the fully closed state by the first signal. In this regard, when the control valve is in the fully closed state when the bath circuit is in the operating state, the heat of the heat medium circulating in the heat medium circulation path is not transmitted to the heat medium in the bath circulation path through the branch path and the liquid-liquid heat exchanger. Therefore, the difference between the temperature of the hot water supply path detected by the first temperature sensor and the temperature of the hot water return path detected by the second temperature sensor is considered to be smaller than when the heat medium is supplied to the liquid-liquid heat exchanger. Therefore, when the water heater performs the third control to set the control valve to the fully closed state when the bath circuit is in the operating state, and after the third control, if the difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor is equal to or greater than a predetermined temperature difference, it is determined that the control valve is not in the fully closed state. By adopting such a method, the water heater can not only inspect whether the control valve is in the fully open state, but also inspect whether the control valve is in the fully closed state. Moreover, since the water heater does not have to be equipped with many switches or the like to inspect whether the control valve is in the fully closed state, it is easy to reduce the number of parts and the manufacturing cost. In this specification, "the third control for setting the control valve to the fully closed state when the bath circuit is in the operating state" includes "the control for setting the control valve to the fully closed state during the water filling operation in which hot water is supplied from the hot water supply circuit to the bath circuit and hot water is supplied from the bath circuit to the bathtub", and also includes "the control for setting the control valve to the fully closed state during the operation in which hot water is circulated in the bath circulation path". In this specification, "the bath circuit is in the operating state" includes the operating state in which hot water is circulated in the bath circulation path and the water filling operation state in which hot water is supplied from the hot water supply circuit to the bath circuit and hot water is supplied from the bath circuit to the bathtub.

[0019] 〔6〕 When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, the operation of the heating circuit is permitted and the introduction of hot water into the external bathtub is prohibited The water heater according to any one of 〔1〕 to 〔5〕.

[0020] In the water heater and space heater of the above [6], when an abnormality occurs such that the switch does not output the first signal when in the fully open state, that is, an abnormality that there is a risk that the control valve cannot be properly controlled, by prohibiting the introduction of hot water into the external bathtub, it is possible to suppress the heated heat medium from being supplied to the liquid-liquid heat exchanger at an unexpected time and the hot water that has warmed up at an unexpected time from being supplied to the external bathtub. On the other hand, since the influence on the heating circuit side is small even if the control valve is abnormal, the operation of the heating circuit is allowed, thereby improving convenience.

[0021] 〔7〕When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, it notifies that the control valve is abnormal. The water heater and space heater according to any one of [1] to [6].

[0022] The water heater and space heater of the above [7] can notify the outside that an abnormality has occurred in the control valve.

[0023] 〔8〕When the condition for reducing the opening degree of the control valve is satisfied when the control valve is in the fully open state, the control device determines whether the switch outputs the first signal even if a signal to close the control valve in the fully open state by a predetermined opening degree is given. The water heater and space heater according to any one of [1] to [7].

[0024] The water heater and space heater of the above [8] can determine whether it has operated to the extent that the first signal is not output when a signal to close the control valve in the fully open state by a predetermined opening degree is given when closing the control valve in the fully open state. Therefore, this water heater and space heater can more quickly determine whether the control valve has moved in the closing direction.

[0025] 〔9〕A water heating and space heating system including the water heater and space heater according to any one of [1] to [7], and a heat dissipation terminal having a terminal flow path through which a heat medium flows and radiating the heat of the heat medium flowing through the terminal flow path.

[0026] <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 1. The water 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 hot water supply operation, automatic water filling operation, post - heating operation, heating operation, etc.

[0027] The water heater 1 is provided with a housing 1A configured as a metal casing inside the housing, and a first combustion system part 5 and a second combustion system part 6 are formed inside the housing 1A. The housing 1A is configured as, for example, a metal can body or a metal box body, and houses a hot water supply burner 8A as an example of a first burner, a heating burner 33A as an example of a second burner, a hot water supply side heat exchanger 7 as an example of a first heat exchanger, a heating side heat exchanger 32 as an example of a second heat exchanger, etc. The first combustion system part 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 part 6 is a combustion system that performs gas combustion and water heating during a heating operation or a post - heating operation.

[0028] The hot water supply circuit 2 is a circuit that heats water supplied from outside the water 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 part 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 part 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.

[0029] 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 unit 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.

[0030] The hot water supply circuit 2 further includes a water supply pipe 11, a water supply control valve 13A, a water flow sensor 14, a hot water outlet pipe 10, a bypass pipe 12, a bypass control valve 13B, a thermistor 15A (hot water supply inner cylinder thermistor), a thermistor 15B (hot water supply and 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 water supply 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.

[0031] 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 bypass control valve 13B (bypass control valve) is provided in the bypass pipe 12. The bypass 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 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. 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 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. Specifically, it 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 control device 70 described later.

[0032] 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 via a 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. A solenoid 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.

[0033] 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, etc.

[0034] 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 branch path 51 and the hot water flowing through the bathtub circulation path 63. When the temperature of the heat medium flowing through the bathtub heating branch path 51 is higher than the temperature of the hot water flowing through the bathtub circulation path 63, the hot water flowing through the bathtub circulation path 63 is heated by the heat medium.

[0035] 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 branch path 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 operates, the bathtub circulation path 63 functions as a flow path for deriving hot water from the bathtub 52 provided outside the water heater 1, and functions as a flow path for circulating the derived hot water and introducing it into the bathtub 52. The bathtub return pipe 54 is provided with a bathtub circulation pump 55 that causes the hot water within the bathtub return pipe 54 to flow in a predetermined direction, and a water flow switch 57 that detects that hot water at a predetermined flow rate or more 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 first temperature sensor 64 as a bathtub supply thermistor that detects 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 second temperature sensor 65 as a bathtub return thermistor that detects the temperature of the hot water flowing into the bathtub return pipe 54 from the bathtub 52.

[0036] A drop pipe 59 is connected to the bathtub return pipe 54 in a configuration branched from the hot water discharge pipe 10. The drop pipe 59 communicates with the bathtub return pipe 54. The drop pipe 59 is provided with a hot water supply solenoid valve 60, a drop water volume sensor 61, a plurality of check valves 62, and the like. When the hot water supply solenoid valve 60 provided in the drop 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 drop pipe 59.

[0037] 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 radiation terminal) via the heat medium circulation path 48. 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 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 from the hot water supply combustion chamber 5A by a partition member 80 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.

[0038] 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.

[0039] 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 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 provided above the heating-side first heat exchanger 32A. The heating-side heat exchanger 32 heats the heat medium (the heat medium flowing through the heat medium circulation path 48) 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.

[0040] 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, and forms the flow path of the heat medium. The heat medium circulation path 48 includes a common forward flow path 38K as the heating forward pipe, a first internal flow path 38A as the heating high-temperature forward pipe, a second internal flow path 38B as the heating low-temperature forward pipe, and a common flow path 38C as the heating return pipe.

[0041] 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 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 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 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 flow path 38C.

[0042] 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 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.

[0043] 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 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.

[0044] 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 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 flow path 38C is the inflow portion 35A, and the downstream end of the common flow path 38C is connected to the inlet portion 36C of the expansion tank 36. The common 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 the heat medium to flow through the heating-side heat exchanger 32 (heating-side second heat exchanger 32B). The common 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.

[0045] 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 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 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.

[0046] The common 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 flow path 38K. The heating circulation pump 37 causes the heat medium in the common flow path 38K to flow from the expansion tank 36 side to the branch portion 38J side.

[0047] The second internal flow path 38B is provided in a configuration where a plurality of internal branch paths 38F branch off. A second 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 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 dressing room. The second heat radiation terminal 39Z is, for example, a low-temperature heating terminal such as floor heating in a dressing room.

[0048] 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 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.

[0049] 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.

[0050] 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 flow path 38C, the first internal flow path 38A, and the first heat dissipation terminal 39A, and also circulates through the common 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 first 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 second valve 39G which is a thermostatic valve inside the appliance.

[0051] As shown in FIG. 1, a branch path 51 for bath heating is provided in a configuration branched from the first internal flow path 38A. The branch path 51 for bath heating branches from a position on the downstream side of the heating-side heat exchanger 32 in the heat medium circulation path 48 (specifically, the downstream side of the heating-side first heat exchanger 32A), and forms a flow path for guiding the heat medium flowing through the heat medium circulation path 48 to the bath heat exchanger 50 side. The branch path 51 for bath heating is connected between the first internal flow path 38A and the common flow path 38C so as to communicate with each other. A control valve 58 is provided on the upstream side of the bath heat exchanger 50 in the branch path 51 for bath heating. The control valve 58 is configured to open and close the branch path 51 for bath heating, and is configured to switch between a closed state in which the water flow passing through itself in the branch path 51 for bath heating is blocked, and an open state in which the water flow passing through itself in the branch path 51 for bath heating is allowed.

[0052] 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 (thermistor, water volume sensor, switch, 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 changing room as a means for detecting the temperature in the changing 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.

[0053] 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 water flow, 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 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, 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.

[0054] 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 controller 71 or the bath remote controller 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 indicates 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.

[0055] (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 controller 71 or the bath remote controller 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 controller 71 or the bath remote controller 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 into 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.

[0056] After the control device 70 starts supplying hot water to the bathtub 52 in this way, it 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 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 controller 71 or the bath remote controller 72 of the end of the hot water filling.

[0057] (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 controller 71 or the bath remote controller 72 is pressed, the control device 70 sets the reheat temperature to the target temperature (e.g., 40°C) set by the hot water supply remote controller 71 or the bath remote controller 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 temperature sensor 65 has reached the target temperature. When it is confirmed that the temperature has 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 controller 71 or the bath remote controller 72 of the end of the reheat.

[0058] 3. Configuration for supplying the 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 into internal flow paths to the external first heat dissipation terminal 39A and second heat dissipation terminal 39Z.

[0059] 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. On the bath circuit 4 side branched at the reheat branch portion 56, the bath heating branch path 51 passes through the bath heat exchanger 50 and is connected to the common 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.

[0060] The bypass flow path 46 is provided between the common 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 flow path 38C and the first internal flow path 38A.

[0061] 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 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.

[0062] Outside the hot water supply and heating apparatus 1, a first heat radiation terminal 39A to which the heat medium is supplied from the hot water supply and heating apparatus 1 and which communicates with the heat medium circulation path 48, and a second heat radiation terminal 39Z are provided. The first heat radiation terminal 39A has a first terminal flow path 38G through which the heat medium flows, and radiates the heat of the heat medium flowing through the first terminal flow path 38G. In the space near the first heat radiation terminal 39A, the air is heated by the heat of the heat medium flowing through the first terminal flow path 38G being radiated. The first heat radiation terminal 39A is configured as a high-temperature heating terminal. The second heat radiation terminal 39Z has a second terminal flow path 38H through which the heat medium flows, and radiates the heat of the heat medium flowing through the second terminal flow path 38H. In the space near the second heat radiation terminal 39Z, the air is heated by the heat of the heat medium flowing through the second terminal flow path 38H being radiated. 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 supply and heating apparatus 1.

[0063] The supply of the heat medium to the first terminal flow path 38G is switched between a state of blocking the supply of the heat medium and a state of permitting it by opening and closing the first valve 39H. When the first valve 39H is open, it is allowed for the heat medium to pass through the first 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 first valve 39H. When the first valve 39H is closed, it is blocked for the heat medium to pass through the first 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 first valve 39H. The supply of the heat medium to the second terminal flow path 38H is switched between a state of blocking the supply of the heat medium and a state of permitting it by opening and closing the second valve 39G. When the second valve 39G is open, it is allowed for the heat medium to pass through the second 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 second valve 39G. When the second valve 39G is closed, it is blocked for the heat medium to pass through the second 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 second valve 39G. Both the first valve 39H and the second valve 39G are thermostatic valves. The thermostatic valve, for example, expands an expansion body with the heat of a heating element (Positive Temperature Coefficient) when the power is turned on, pushes a piston to open the valve so that hot and cold water can flow, and when the power is turned off, the heating element naturally dissipates heat to contract the expansion body and close the valve.

[0064] The heat medium flowing into the inflow portion 35A circulates in the heat medium circulation path 48 in the hot water heater 1. Specifically, the heat medium flows downstream from the inflow portion 35A through the common 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 flowing toward the branch portion 38J is divided at the branch portion 38J into the heat medium heading toward the first internal flow path 38A and the heat medium heading 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.

[0065] 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.

[0066] A first valve 39H that opens and closes the first terminal flow path 38G, a second valve 39G that opens and closes the second internal flow path 38B, and a heating circulation pump 37 are controlled by a control device 70. The control device 70 is electrically connected to each of the first valve 39H, the second valve 39G, and the heating circulation pump 37, and performs opening and closing control of the first valve 39H and the second valve 39G and drive control of the heating circulation pump 37.

[0067] 4. Configuration for detecting a failure of a control valve A bath heating branch path 51 of the bath circuit 4 is provided in a configuration branched from the first internal flow path 38A of the heating circuit 3. The bath heating branch path 51 corresponds to an example of a branch path. The bath heating branch path 51 branches from a position downstream of the heating-side heat exchanger 32 in the heat medium circulation path 48 (more specifically, a position between the heating-side first heat exchanger 32A and the first heat dissipation terminal 39A in the first internal flow path 38A), and forms a flow path that guides the heat medium flowing through the heat medium circulation path 48 toward the bath heat exchanger 50 side. When the control valve 58 is in an open state, a part of the heat medium in the first internal flow path 38A that has passed through the heating-side first heat exchanger 32A flows into the bath heating branch path 51 and circulates so as to flow into the common flow path 38C from the bath heating branch path 51.

[0068] The control valve 58 is a valve provided upstream of the bathtub heat exchanger 50 in the bathtub heating branch path 51 and has a switch 88. This switch 88 is configured as a limit switch and enters a first state in which it outputs a predetermined first signal (for example, an on signal) when the control valve 58 is in the fully open state where it is most open, and enters a second state in which it outputs a second signal (for example, an off signal) different from the first signal when the control valve 58 is not in the fully open state. In the present embodiment, the control valve 58 is configured such that the second signal is output in all states (second state) other than the fully open state (such as half open or fully closed), but it is not limited to this. For example, the second signal may be output with the fully closed state where it is most closed as the second state. The switch 88 can employ various types of switches as long as it can output at least the first signal.

[0069] The control valve 58 can be adjusted to an arbitrary opening degree from the fully open state through the half open state (intermediate open position) to the fully closed state. The control valve 58 is connected to a motor 87, and when a pulse voltage (and current) is supplied to the motor 87 in response to a control signal from the control device 70, it reaches an opening degree corresponding to the pulse voltage (and current). For example, when a specified pulse voltage (and current) corresponding to the fully open state is supplied, the control valve 58 connected to the motor 87 becomes fully open, and when a specified pulse voltage (and current) corresponding to the half open state is supplied, the control valve 58 connected to the motor 87 becomes half open, and when a specified pulse voltage (and current) corresponding to the fully closed state is supplied, the control valve 58 connected to the motor 87 becomes fully closed. Note that, for example, it may be held in the fully open state or the fully closed state by the elastic repulsive force of the elastic body in a state where no drive current is supplied. In this case, when the pulse voltage (and current) stops being supplied (when the drive current is cut off), it may return to the fully open state or the fully closed state by the elastic repulsive force.

[0070] The control valve 58 is configured to open and close the hot water supply branch path 51 for bathtub heating. It is configured to switch between a closed state (fully closed state) that blocks the water flow passing through itself in the hot water supply branch path 51 and an open state (fully open state) that allows the water flow passing through itself in the hot water supply branch path 51. That is, when the control valve 58 is in the open state (fully open state), the heat medium upstream of the control valve 58 is allowed to flow through the control valve 58 and through the portion in the pipeline 50A in the hot water supply branch path 51 for bathtub heating. When the control valve 58 is in the closed state (fully closed state), the heat medium upstream of the control valve 58 is blocked from passing through the control valve 58, and no heat medium flows from the upstream side of the control valve 58 to the portion in the pipeline 50A in the hot water supply branch path 51 for bathtub heating.

[0071] 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 drawn from the 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 hot water supply branch path 51 for bathtub heating and the hot water flowing through the bathtub circulation path 63. When the temperature of the heat medium flowing through the hot water supply branch path 51 for bathtub heating is higher than the temperature of the hot water flowing through the pipeline 50A, the heat of the heat medium flowing through the hot water supply branch path 51 for bathtub heating is transferred to the hot water flowing through the pipeline 50A, and the hot water in the pipeline 50A is configured to be heated.

[0072] The bath heat exchanger 50 is provided with a pipe 50A that forms part of the bath circulation path 63, and is configured such that the bath heating branch path 51 is disposed within the pipe 50A. The bath circulation path 63 is configured to include the pipe 50A, the bath supply pipe 53, and the bath return pipe 54. When the bath circulation pump 55 operates, the bath circulation path 63 functions as a flow path for deriving hot water from the bathtub 52 provided outside the water heater 1, and functions as a flow path for circulating the derived hot water and introducing it into the bathtub 52. The bath return pipe 54 is provided with a bath circulation pump 55, a water flow switch 57, a pressure sensor, etc. The bath 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 bath circulation pump 55 operates. The bath 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 bath circulation pump 55 operates. The pipe 50A forms a flow path for flowing hot water from the bath return pipe 54 side to the bath supply pipe 53 side when the bath circulation pump 55 operates. A first temperature sensor 64 is provided in the bath supply pipe 53. A second temperature sensor 65 is provided in the bath return pipe 54. The second temperature sensor 65 is provided between the connection portion 89 and the bath circulation pump 55 on the downstream side of the connection portion 89 of the bath return pipe 54 with the drop pipe 59.

[0073] The drop pipe 59 branches from the hot water outlet pipe 10 and is provided with a hot water supply solenoid valve 60, a drop water volume sensor 61, a check valve 62, etc. During the water filling operation of the bath, the hot water supply circuit 2 is operated, and the hot water supply solenoid valve 60 provided in the drop pipe 59 is opened, so that the hot water heated by the hot water supply circuit 2 is supplied to the bathtub 52 through the drop pipe 59.

[0074] 5. Processing for determining an abnormality of the control valve 58 When a predetermined start condition is satisfied in the hot water supply and heating apparatus 1 (for example, when the power supply of the hot water supply and heating apparatus 1 is turned on), the control device 70 starts the process shown in FIG. 2. After starting the process shown in FIG. 2, the control device 70 determines whether a predetermined operation start condition is satisfied. The case where a predetermined operation start condition is satisfied means, for example, a case where at least one of the conditions for starting the heating-only operation, the supplementary heating operation, and the freeze-prevention operation is satisfied. The condition for starting the heating-only operation may be, for example, "performing a predetermined operation for instructing the start of the operation of the heating circuit 3 by the remote controls 71 to 73 in a state where the supplementary heating operation is not being performed", or may be other conditions. The condition for starting the supplementary heating operation may be, for example, "performing a predetermined operation for instructing the supplementary heating operation by the remote controls 71 to 73", or may be other conditions. The condition for starting the freeze-prevention operation may be, for example, "the temperature detected by a thermistor provided in the hot water supply and heating apparatus 1 (for example, a thermistor for detecting the outside air temperature) is equal to or lower than a predetermined value", or "the set time has arrived", or may be other conditions.

[0075] After starting the control shown in FIG. 2, the control device 70 repeatedly makes a NO determination in step S11 until it determines that the predetermined start condition is satisfied in step S11. When it determines that the predetermined start condition is satisfied in step S11, the process proceeds to step S12.

[0076] In step S12, the control device 70 controls to enter an operating state corresponding to the operation start condition determined to be satisfied in step S11. For example, when it is determined in step S11 that the condition for starting the heating-only operation is satisfied, the control device 70 starts or continues the operation of the heating circuit 3 and outputs a control signal so that the control valve 58 is in the fully closed state. The heating-only operation includes an operation in which "while performing a heating operation of burning the heating burner 33A, the bath circulation pump 55 of the bath circuit 4 is stopped and the automatic hot water supply operation is also stopped". Alternatively, when it is determined in step S11 that the condition for starting the reheating operation of the bath is satisfied, the control device 70 starts or continues the operation of the heating circuit 3 and outputs a control signal so that the control valve 58 is in the fully open state. Alternatively, when it is determined in step S11 that the condition for starting the anti-freezing operation is satisfied, the control device 70 outputs a control signal so that the control valve 58 is in the intermediate position (half-open state). The anti-freezing operation is an operation for preventing freezing when hot water supply or heating is not performed. The burners 8A and 33A are not burned, and the heating circulation pump 37 is driven to circulate the heat medium. The detailed control in the operating state will be described later.

[0077] After step S12, the control device 70 proceeds with the process to step S13 and determines whether the operation has ended. The control device 70 repeats the process of step S13 until the operation ends (when the answer is No in step S13). When the operation ends (when the answer is Yes in step S13), the control device 70 proceeds with the process to step S14 and once enters a standby state where operations such as hot water supply and heating are not performed. After setting the standby state in step S14, the control device 70 proceeds with the process to step S15. In step S15, the control device 70 outputs a control signal to the motor 87 of the control valve 58 to fully open the control valve 58. After step S15, the control device 70 proceeds with the process to step S16. Step S15 is an example of the first control.

[0078] When the control device 70 outputs a control signal in step S15, if no abnormality such as a failure occurs in the control valve 58, the control valve 58 fully opens according to the control signal, and a first signal is output from the switch 88. Therefore, in step S16 of step S15, the control device 70 determines whether a first signal is input from the switch 88. When a first signal is input from the switch 88 (Yes in step S16), the control valve 58 operates normally and becomes fully open according to the control signal, and it is highly likely that no failure or the like has occurred in the control valve 58. Therefore, when the control device 70 determines in step S16 that the first signal has been input, it determines in step S17 that the control valve 58 is operating normally and returns to step S11. At this time, for example, it may be configured to display (notify) to the remote controls 71 to 73 or the like that the control valve 58 is normal (no abnormality has occurred).

[0079] On the other hand, when a first signal is not input from the switch 88 (when a second signal is input. No in step S16), the control valve 58 is not in the fully open state, and it is highly likely that a failure or the like has occurred in the control valve 58. Therefore, when the control device 70 determines in step S16 that the first signal is not input from the switch 88, it determines in step S18 that an abnormality has occurred in the control valve 58. When the control device 70 determines in step S18 that an abnormality has occurred, for example, it may display to the remote controls 71 to 73 that an abnormality has occurred in the control valve 58 or notify the outside by means of communication. When an abnormality has occurred in the control valve 58, there is a concern about problems such as the supply of unintentionally high-temperature hot water to the bathtub circuit 4 side. Therefore, when the control device 70 determines in step S18 that an abnormality has occurred in the control valve 58, in the subsequent step S19, it outputs a control signal to fully close the control valve 58 to the control valve 58 (motor 87 thereof) and advances the process to step S20.

[0080] Next, in step S20, the control device 70 enables heating (allows heat dissipation to the heat dissipation terminals 39A and 39Z in the heating circuit 3), and since the control valve 58 is in the fully closed state, heat transfer to the hot water circulating in the bathtub circulation path 63 in the bathtub circuit 4 is blocked, so (even if there is an operation instruction for the bathtub circuit 4 from the bathtub remote control 72), the introduction of hot water into the bathtub 52 is prohibited. Specifically, while the combustion of the heating burner 33A and the circulation of the heat medium by driving the heating circulation pump 37 are performed, the bathtub circulation pump 55 stops and does not circulate the hot water in the bathtub circulation path 63, and the hot water supply solenoid valve 60 is closed to stop the supply of hot water to the bathtub 52 through the drop pipe 59. When an abnormality such as a failure occurs in the control valve 58, since the user's disadvantage is likely to increase due to the supply of hotter hot water to the bathtub side than the heating supply, the heating operation is allowed to minimize the decrease in convenience, and the introduction (topping up or hot water addition) of hot water into the bathtub 52, which is an example of an external bathtub provided outside the hot water supply and heating machine 1, is prohibited, thereby suppressing the disadvantage to the user caused by the abnormality of the control valve 58.

[0081] When the control device 70 determines that the control valve 58 is abnormal in step S18, together with or instead of the control in step S20, the control device 70 may perform an operation of notifying that the control valve 58 is abnormal. The "operation of notifying that the control valve 58 is abnormal" may, for example, display an error message or error code indicating that the control valve 58 is abnormal on the display unit, emit a sound indicating that the control valve 58 is abnormal by a speaker or buzzer, or transmit information indicating that the control valve 58 is abnormal to an external device by communication.

[0082] The control during the operation state (step S12) will be described with reference to FIG. 3. When the control device 70 performs step S12 in FIG. 2, it executes according to the flow as shown in FIG. 3. First, in step S21, it starts the operation corresponding to the condition established in step S11 (FIG. 2). After starting the operation in step S21, the control device 70 advances the process to step S22 and determines whether the operation start condition established in step S11 is an instruction to perform different operation states that require a change in the opening degree of the control valve 58. The control valve 58 is fully closed during the sole heating operation, fully open during the operation of the bath circuit 4 (reheating operation), and at the intermediate open position (half open) during the freeze prevention operation. Note that when none of the sole heating operation, reheating operation, and freeze prevention operation is performed and the combustion and circulation in the heating circuit 3 have stopped during the heating operation stop, the control valve 58 is, for example, in the fully open state. If there is no instruction to change the operation state involving a change in the opening degree of the control valve 58 (No in step S22), the process in FIG. 3 ends. If there is an instruction to change the operation state involving a change in the opening degree of the control valve 58 (Yes in step S22), the process advances to step S23.

[0083] When the control device 70 advances the process to step S23, it determines whether the establishment of the operation start condition in step S11 is a condition for closing the control valve 58 in the state where the first signal is output from the switch 88 (the state where the limit switch is ON) (that is, whether it is a condition for changing the control valve 58 from the fully open state to the fully closed or half open state). The case where the control valve 58 is in the fully open state is, for example, during the reheating operation or the heating operation stop. The case where the control valve 58 is fully closed or half open is during the sole heating operation or the freeze prevention operation. That is, when it is in the reheating operation state or the heating operation stop state until immediately before step S11 and the operation start condition for starting the sole heating operation or the freeze prevention operation is established in step S11, since it is a condition for changing the control valve 58 from the fully open state to the fully closed or half open state, the control device 70 determines Yes in step S23.

[0084] When the control device 70 determines Yes in step S23, it advances the process to step S31 and starts outputting a control signal for controlling the control valve 58 in the closing direction so as to set the opening degree corresponding to the operating condition established in step S11. For example, when the control valve 58 is configured to be operated by a stepping motor, it starts outputting a control signal for driving the number of steps corresponding to the operating condition established in step S11. After starting the output of the control signal in step S31, the control device 70 determines in step S32 whether the default output of the control signal has been completed.

[0085] The default output is "output of a control signal for closing the control valve 58 with an opening degree in the fully open state to a certain degree until the first signal is no longer output from the switch 88". Specifically, it is the output of a control signal with a predetermined number of steps that is smaller than the number of steps required to be given to the stepping motor to close the control valve 58 in the fully open state to the fully closed state and greater than 0. That is, when a control signal with the above-mentioned predetermined number of steps in the closing direction of the control valve 58 is given to the stepping motor of the control valve 58 in the fully open state, the control valve 58 closes until the opening degree at which the first signal is no longer output from the switch 88. Therefore, in step S32, the control device 70 determines "whether the output of the control signal with the above-mentioned predetermined number of steps in the closing direction of the control valve 58 has been completed since the output of the control signal was started in step S31". If it has been completed, the process advances to step S33. If it has not been completed, the determination in step S32 is repeated.

[0086] When the control device 70 proceeds with the process to step S33, it determines whether a first signal is input from the switch 88 in step S33. If the first signal is not input from the switch 88 at the time of step S33 (in the case of No in step S33), the control valve 58 operates according to the control signal made from step S31 to step S33, and it is highly likely that the control valve 58 is closed to the extent that the first signal is not output from the switch 88, and since it is highly likely that the control valve 58 is operating normally in the closing direction, the control valve 58 is judged to be normal in step S34. When the control device 34 determines that the control valve 58 is normal in step S34, in step S35, after changing the opening degree of the control valve 58 to the opening degree corresponding to the operating condition established in step S11, the process proceeds to step S13 in FIG. 2.

[0087] When the first signal is input from the switch 88 at the time of step S33 (in the case of Yes in step S33), the control valve 79, even if a control signal (the control signal of the above-mentioned predetermined number of steps) is given to the stepping motor of the control valve 58 from step S31 to step S33, the control valve 58 has not operated to the extent that the first signal is not output from the switch 88, and since it is highly likely that an abnormality such as a failure has occurred in the control valve 58, it is judged that an abnormality has occurred in the control valve 58 in step S36. Step S36 is an example of the fourth judgment. When the control device 70 determines that an abnormality has occurred in the control valve 58 in step S36, it controls the control valve 58 to be fully closed in step S37. After step S37, the control device 70, in step 38, notifies an abnormality of the control valve 58. When notifying an abnormality in step S38, it may display that an abnormality has occurred in the control valve 58 on the remote controller 71 or the like, or notify it externally by communication means. When the control device 70 finishes the processes of steps S37 and S38, it ends the process of the operating state.

[0088] When the control device 70 determines No in step S23 of FIG. 3 (when the establishment of the operation start condition in step S11 is the establishment of the condition for changing the opening degree of the control valve and is not the establishment of the condition for controlling the control valve in the fully open state in the closing direction), the process proceeds to step S24. For example, when the establishment of the operation start condition in step S11 is the establishment of the condition for changing the operation state from the heating-only operation to the supplementary heating operation, since the change in the opening degree of the control valve 58 is a change in the operation state that requires a change, and it is a change from the fully closed state to the fully open state, the process proceeds to step S24.

[0089] In step S23, the control device 70 outputs a control signal to the control valve 58 (motor 87 thereof) to fully open the control valve 58 and proceeds to step S25. Step S24 is an example of the second control. If no abnormality such as a failure has occurred in the control valve 58, the control valve 58 will open fully in response to the control signal, and a first signal will be output from the switch 88. Therefore, in step S25, it is determined whether the first signal has been input from the switch 88. When the first signal is input from the switch 88 (Yes in step S25), since the control valve 58 has operated in response to the control signal to be in the fully open state and it is highly likely that no abnormality such as a failure has occurred in the control valve 58, in step S26, it is determined that the control valve 58 is operating normally. Step S26 is an example of the second determination. Next, after changing the opening degree of the control valve 58 according to the instruction of the operation state in step S27, the process proceeds to step S13 of FIG. 2.

[0090] On the other hand, when the first signal is not input from the switch 88 in step S25 of FIG. 3 (when the second signal is input; when the answer is No in step S25), the control valve 58 is not fully open, and there is a high possibility that an abnormality such as a failure has occurred in the control valve 58. Therefore, it is determined in step S28 that an abnormality has occurred in the control valve 58. Step S28 is an example of the second determination. When it is determined that an abnormality has occurred in the control valve 58, since there is a concern that hot water at an unintended high temperature may be supplied to the bathtub circuit 4 side when the control valve 58 is open, the control device 70 controls the control valve 58 to be fully closed in step S29. In this case, it may be displayed on the remote control 71 or the like that an abnormality has occurred in the control valve 58, or it may be notified to the outside by the communication means. Further, when it is determined that an abnormality has occurred in the control valve 58, for example, heat dissipation to the heat dissipation terminals 39A and 39Z in the heating circuit 3 is permitted, and (even if there is an operation instruction for the bathtub circuit 4 from the bathtub remote control 72), the introduction of hot water into the bathtub 52 may be prohibited. When the control valve 58 is controlled to be fully closed in step S29, the processing of the operation state is terminated.

[0091] Next, the monitoring process during the bathtub filling operation will be described. When a predetermined start condition is satisfied (for example, when the power supply of the hot water supply and heating machine 1 is turned on), the control device 70 starts the monitoring process shown in FIG. 5. When the control device 70 starts the monitoring process shown in FIG. 5, it operates so as to execute the control below step S43 during the control of the hot water filling operation of the bathtub. In the representative example shown in FIG. 5, after starting the control shown in FIG. 5, the control device 70 determines whether or not full-closed control has been performed on the control valve 58. If full-closed control has not been performed (No in step S41), the process of step S41 is repeated. When the control device 70 performs full-closed control on the control valve 58 (Yes in step S41), it proceeds to step S42 and determines whether or not it is a hot water filling operation of the bathtub. When the hot water filling operation of the bathtub is not being performed (No in step S42), the control device 70 ends the process shown in FIG. 4. On the other hand, when the hot water filling operation of the bathtub is being performed (Yes in step S42), the control device 70 advances the process to step S43 and determines whether or not the temperature difference TD between the first temperature sensor 64 and the second temperature sensor 65 is within a predetermined range. That is, when the start of the hot water filling operation of the bathtub is made, the control device 70 fully closes the control valve 58, so Yes in step S41 and Yes in step S42, and thus the processes after step S43 are performed. The detected temperatures of the first temperature sensor 64 and the second temperature sensor 65 are continuously input to the control device 70, and the control device 70 continuously monitors the temperatures of the first temperature sensor 64 and the second temperature sensor 65. "Within a predetermined range" of the temperature difference TD is a range in which a temperature difference that allows the control valve 58 to be determined to be in an open state (by heating the hot water in the bathtub forward pipe 53 in the bathtub circulation path 63 due to the inflow of high-temperature hot water into the branch path 51 for heating the bathtub) is generated. The value of "within a predetermined range" is stored in the memory of the control device 70 in advance, for example. When the control device 70 determines in step S43 that the temperature difference TD is within a predetermined range (Yes in step S43), it is highly likely that the heat on the heating circuit 3 side is not transmitted to the hot water in the bathtub forward pipe 53 in the bathtub circulation path 63, and since it can be determined that the control valve 58 is operating normally and is in a fully closed state, the process ends.

[0092] On the other hand, when the control device 70 determines in step S43 that the temperature difference TD is not within the predetermined range (No in step S43), it is highly likely that the heat of the hot water on the heating circuit 3 side is transferred to the hot water in the hot water supply pipe 53 in the bath circulation path 63, and it is highly likely that the control valve 58 is in the open state due to an abnormality of the control valve 58. Therefore, in step S44, it is determined that the control valve 58 is not in the fully closed state (is in the open state). Step S44 is an example of the third determination. Further, although a fully closed control signal is output to the control valve 58, since it is necessary to notify the outside that the control valve 58 is in the open state and an abnormality has occurred, the control device 70 displays the abnormality of the control valve 58 on the remote controllers 71 to 73 in step S45, or notifies the outside of the abnormality of the control valve 58 by means of communication means or the like, and ends the process of FIG. 5. In addition to or instead of performing the abnormality notification in step S45, the same control as in step S20 is performed, allowing the combustion of the heating burner 33A and the circulation of the heat medium by driving the heating circulation pump 37, while stopping the bath circulation pump 55 to prevent the hot water in the bath circulation path 63 from circulating, closing the hot water supply solenoid valve 60, and stopping the supply of hot water to the bathtub 52 through the drop pipe 59 may be acceptable.

[0093] 6. Example of Effect When the operation state ends, the control device 70 outputs a control signal so that the control valve 58 is in the fully open state. At this time, if no abnormality such as a failure occurs in the control valve 58, the control valve 58 becomes the first state in the fully open state, and a first signal is output from the switch 88 to the control device 70. When the control device 70 receives the first signal from the switch 88, it determines by the first determination that the control valve 58 is normal (no abnormality has occurred). On the other hand, when the first signal is not input from the switch 88, it is determined by the first determination that an abnormality has occurred in the control valve 58. Thereby, when the operation state ends, it is possible to determine the presence or absence of an abnormality in the control valve 58, so that it is possible to suppress the disadvantage to the user due to the failure to detect the abnormality of the control valve 58.

[0094] When an abnormality occurs in the control valve 58, a control signal is output so that the control valve 58 is in a fully closed state. (Although the control valve 58 does not necessarily become fully closed due to a failure or the like), since the high-temperature hot water in the heat medium circulation path 48 is not transmitted to the hot water in the bath circulation path 63, it is possible to suppress the disadvantage given to the user when using the bath when an abnormality occurs in the control valve 58.

[0095] <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.

[0096] In the above configuration, the fully closed state is detected by the temperature difference TD between the first temperature sensor 64 and the second temperature sensor 65, but it is not limited thereto. For example, in addition to the first limit switch that outputs the first signal, a second limit switch that outputs a second signal when the control valve 58 reaches the fully closed state where it is most closed may be used. Also, a second signal or the like may be output when the control valve 58 is in the intermediate open position (half-open state) during the freeze prevention operation.

[0097] 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 that all modifications within the scope shown by the claims or within the scope equivalent to the claims are included.

Explanation of Reference Numerals

[0098] 1: Water Heater 1A: Housing 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 (first heat exchanger) 7Z: Fin 8: Hot water supply side burner unit 8A: Hot water supply burner (first burner) 9A: Burner block 9B: Burner block 9C: Burner block 10: Hot water outlet pipe 11: Water supply pipe 20: Fan 20A: Drive source 20B: Rotating body 32: Heating side heat exchanger (second heat exchanger) 32A: Heating side first heat exchanger 32B: Heating side second heat exchanger 33: Heating side burner unit 33A: Heating burner (second burner) 34A: Burner block 34B: Burner block 35A: Inlet part 35B: First outlet part 35C: Second outlet part 36: Expansion tank 36C: Inlet part 36B: Outlet part 37: Heating circulation pump 38A: First internal flow path 38B: Second internal flow path 38C: Common return flow path 38K: Common forward flow path 38J: Branch part 39A: First heat dissipation terminal (heating terminal) 39Z: Second heat dissipation terminal (heating terminal) 38G: First terminal flow path 38H: Second terminal flow path 39H: First valve 39G: Second valve 46: Bypass flow path 48: Heat medium circulation path 50: Bathtub heat exchanger (liquid-liquid heat exchanger) 51: Branch path for bathtub heating (branch path) 52: External bathtub 56: Afterburning branch 58: Control valve 63: Bathtub circulation path 70: Control device 88: Switch 87: Motor

Claims

1. a hot water supply circuit including a first burner for burning gas and a first heat exchanger heated by exhaust gas generated by the first burner, the hot water supply circuit heating water supplied from the outside by the first heat exchanger to supply hot water; a heating circuit including a second burner that burns gas, a second heat exchanger that is heated by exhaust gas generated by the second burner, and a heat medium circulation path that is a path for circulating a heat medium through the second heat exchanger, the heating circuit heating the heat medium by the second heat exchanger and supplying the heat medium to a heating terminal via the heat medium circulation path; A bath circuit having a bath circulation path that circulates hot and cold water drawn from an external bathtub and introduces it into the external bathtub; A liquid-liquid heat exchanger that exchanges heat with the hot water flowing through the bath circulation path; a branch path that branches off from the heat medium circulation path and guides the heat medium that has flowed through the heat medium circulation path to the liquid-liquid heat exchanger; a control valve capable of opening and closing the branch passage from a fully open state to a fully closed state; a switch that outputs a first signal when the control valve is in the fully open state and does not output the first signal when the control valve is not in the fully open state; a control device that controls the opening and closing of the control valve and monitors the output from the switch; Equipped with The control device controls the control valve to the fully closed state during a heating only operation in which the bath circuit is not operated and the heating circuit is operated, controls the control valve to the open state during a re-heating operation in which the heating circuit is operated and the bath circuit is operated, and controls the control valve to the fully open state at least when the heating only operation is completed, and performs a first determination as to whether or not the switch has output the first signal when in the fully open state. Hot water heater.

2. The control device controls the control valve to the fully closed state during the heating only operation, controls the control valve to the fully open state during the re-heating operation, and controls the control valve to an intermediate state having an opening degree larger than that of the fully closed state and smaller than that of the fully open state when a predetermined freeze prevention operation is performed. When any of the heating only operation, the re-heating operation, and the freeze prevention operation has ended, the control valve is in the fully open state and performs the first determination to determine whether or not the switch has output the first signal when the control valve is in the fully open state. The hot water heater according to claim 1.

3. When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, the control device controls the control valve to the fully closed state. The hot water supply and heating machine according to claim 1 or claim 2.

4. The control device When a predetermined change condition for changing the opening degree of the control valve to an opening degree other than the fully open state is satisfied when at least one of the operation of circulating the heat medium in the heat medium circulation path of the heating circuit and the operation of circulating the hot water in the bathtub circulation path of the bathtub circuit is performed, the control device controls the control valve to the fully open state and makes a second determination as to whether the switch outputs the first signal when in the fully open state. When it is determined in the second determination that the switch outputs the first signal when in the fully open state, the opening degree is changed according to the change condition. When it is determined in the second determination that the switch does not output the first signal when in the fully open state, the control device controls the control valve to the fully closed state. The hot water supply and heating machine according to claim 1 or claim 2.

5. A first temperature sensor that detects the temperature of the bathtub forward flow path leading to the external bathtub in the bathtub circulation path, A second temperature sensor that detects the temperature of the bathtub return flow path returning from the external bathtub in the bathtub circulation path, and is provided with When the bathtub circuit is in an operating state, the control device performs a third control to set the control valve to the fully closed state. After performing the third control, when the difference between the temperature detected by the first temperature sensor and the temperature detected by the second temperature sensor is equal to or greater than a predetermined temperature difference, the control device determines that the control valve is not in the fully closed state. The hot water supply and heating machine according to claim 1 or claim 2.

6. When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, the operation of the heating circuit is allowed, and the introduction of hot water into the external bathtub is prohibited. The hot water supply and heating machine according to claim 1 or claim 2.

7. When the control device determines in the first determination that the switch does not output the first signal when in the fully open state, the control device notifies that the control valve is abnormal. The hot water supply and heating machine according to claim 1 or claim 2.

8. When a condition for reducing the opening degree of the control valve when the control valve is in the fully open state is satisfied, the control device determines whether the switch outputs the first signal even if a signal for closing the control valve in the fully open state by a predetermined opening degree is given. The hot water heater according to claim 1 or claim 2.

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