JP5538141B2 - Bath water heater - Google Patents

Description

  The present invention relates to a bath water heater. In particular, the present invention relates to prevention of freezing of a circulation line in a bath water heater provided with a sensible heat recovery type main heat exchanger and a latent heat recovery type sub heat exchanger.

  2. Description of the Related Art Conventionally, as a hot water supply apparatus provided with a sensible heat recovery type main heat exchanger and a latent heat recovery type sub heat exchanger, for example, the one shown in FIG. 2 is known (Patent Document 1). A hot water supply burner 251a is disposed in the hot water supply heat exchanger 250a of the hot water supply apparatus, and a gas pipe 242 for supplying gas is connected to the hot water supply burner 251a. The gas pipe 242 is provided with a plurality of on-off valves 252 for controlling fuel supply / stop to each burner constituting the hot water supply burner 251a. A fan 205 is provided below the hot water supply burner 251a to supply and exhaust the combustion of the hot water supply burner 251a.

  The hot water supply heat exchanging section 250a has a hot water supply sensible heat recovery type main heat exchanger 231 for recovering sensible heat in the combustion gas of the hot water supply burner 251a and a hot water supply sensible heat recovery type main heat exchange above the hot water supply burner 251a. A hot water supply latent heat recovery type auxiliary heat exchanger 232 for recovering the latent heat of the combustion gas is provided further above the unit 231. The sensible heat recovery main heat exchanger 231 for hot water supply includes a pipe 235 for passing water, and plate-like fins 234 that are erected on the outer peripheral surface of the pipe 235 at intervals from each other. Yes.

  In this type of hot water supply apparatus, in order to obtain high thermal efficiency, low-temperature water supplied from the water supply pipe 246 is preheated by recovering the latent heat of the combustion gas in the hot water latent heat recovery type auxiliary heat exchanger 232, From the water supply source, the hot water latent heat recovery type sub heat exchanger 232 and the hot water supply sensible heat recovery type main heat exchanger 231 are arranged in this order so that the heated water is heated by the sensible heat recovery type main heat exchanger 231 for hot water supply. Water is running. Therefore, a water supply pipe 246 through which water from a water supply source is led is connected to the inlet side of the hot water supply latent heat recovery type auxiliary heat exchanger 232, and the outlet side of the hot water supply latent heat recovery type auxiliary heat exchanger 232 and the hot water supply microscope are connected. The inlet side of the heat recovery type main heat exchanger 231 is connected via a connecting pipe 236, and the hot water supply pipe 247 is connected to the outlet side of the hot water sensible heat recovery type main heat exchanger 231.

  Further, in the hot water supply apparatus having the hot water supply latent heat recovery type auxiliary heat exchanger 232, the piping path connecting the hot water supply sensible heat recovery type main heat exchanger 231 and the hot water supply latent heat recovery type auxiliary heat exchanger 232 becomes longer. Even if the water draining operation is performed, water tends to remain in the pipe, and the water in the pipe may be frozen in winter. Therefore, in patent document 1, while connecting the drain pipe 237 to the connection pipe 236 connected with the piping 235a located in the lowest stage among the piping 235 which constitutes the sensible heat recovery type main heat exchanger 231 for hot water supply, A drain plug 238 is provided in the drain pipe 237 to discharge water remaining in the pipes of the sensible heat recovery type main heat exchanger 231 for hot water supply and the latent heat recovery type sub heat exchanger 232 for hot water supply.

  On the other hand, a bath water heater having a reheating function for reclaiming bathtub water in a bathtub has been conventionally known. In this type of bath water heater, a heat exchanging part for reheating the bath water is provided separately from the heat exchanging part for hot water supply as described above, but usually the bath water before reheating is constant. Therefore, a heat exchanging unit having only a sensible heat recovery type heat exchanger is widely used because hot water with a predetermined temperature can be generated by heating in a short time. However, in order to save energy, the latent heat recovery type auxiliary heat exchanger and the sensible heat recovery type main heat exchanger as described above are used in combination in the reheating heat exchange unit separately from the hot water heat exchange unit. It is desirable.

  FIG. 3 is a schematic configuration diagram of a bath water heater in which both of the latent heat recovery-type sub heat exchanger and the sensible heat recovery-type main heat exchanger as described above are provided in the heat exchange section for chasing the bathtub water. is there.

  In this configuration, a sensible heat recovery type main heat exchanger 331 having a hot water sensible heat recovery type main heat exchanger 331 and a hot water supply latent heat recovery type sub heat exchanger 332 as shown in FIG. A heat exchanging section 350b having a heat exchanger 333 and a latent heat recovery type auxiliary heat exchanger 334 is provided. And the bypass pipe 326 is branched and connected to the hot water supply pipe 347 of the hot water supply apparatus, and the bypass pipe 326 passes through the hot water solenoid valve 327 and the flow rate sensor 315, and bath water between the bathtub 330 and the heat exchange unit 350b. Is connected to a pipe constituting a circulation pipe 335 for circulating the gas.

  The circulation line 335 includes a return pipe 335 a that connects the bathtub 330 and the inlet side of the latent heat recovery type auxiliary heat exchanger 334, an outlet side of the latent heat recovery type auxiliary heat exchanger 334, and the sensible heat recovery type main heat exchanger 333. It has a connecting pipe 335 b that connects the inlet side, and an outgoing pipe 335 c that connects the outlet side of the sensible heat recovery type main heat exchanger 333 and the bathtub 330. Further, the outlet side (upstream end) of the return pipe 335a and the inlet side (downstream end) of the forward pipe 335c are connected to a circulation adapter 336 disposed on the side wall so that these pipes and the bathtub 330 are in communication with each other. It is connected.

  In addition, a return pipe 335a between the bathtub 330 and the latent heat recovery-type sub heat exchanger 334 has a circulation pump 301 for circulating bath water between the bathtub 330 and the heat exchange unit 350b in order from the bathtub 330 side. And a water level sensor 318 for detecting the water level of the bathtub 330 and a water flow switch 317 that is turned on when it is detected that water has flowed through the return pipe 335a are disposed. A temperature sensor 316 is provided for detecting the temperature.

  In such a bath water heater, when the reheating operation is started, the bath water circulates through the circulation line 335 by driving the circulation pump 301. At this time, the bathtub water rises up the return pipe 335a from the bathtub 330, is sent to the latent heat recovery type auxiliary heat exchanger 334, is preheated by recovering latent heat in the latent heat recovery type auxiliary heat exchanger 334, and then The preheated water is sent to the sensible heat recovery type main heat exchanger 333 and heated by the heating power of the burner 351b to become hot water, which flows down the forward pipe 335c and is supplied to the bathtub 330. Thereby, thermal efficiency can be improved even in the reheating operation, and an energy-saving bath water heater can be provided.

JP 2007-32935 A

  By the way, when it is going to comprise the bath hot-water supply apparatus which comprised both the latent heat recovery type sub heat exchanger 334 and the sensible heat recovery type main heat exchanger 333 in the heat exchange part 350b as mentioned above, as already stated. In consideration of thermal efficiency, it is necessary to provide a latent heat recovery type sub heat exchanger 334 above the sensible heat recovery type main heat exchanger 333 and downstream of the flow of the combustion gas. Therefore, the connection pipe 335b connected to the lowermost pipe constituting the sensible heat recovery type main heat exchanger 333 is a latent heat recovery type sub heat exchanger 334 positioned above the sensible heat recovery type main heat exchanger 333. Is bent upward, and the lowermost pipe of the sensible heat recovery type main heat exchanger 333 continuous with the connecting pipe 335b is also upward in the sensible heat recovery type main heat exchanger 333. Is bent. As a result, when the reheating operation is finished and the driving of the circulation pump 301 is stopped, water remains in the pipe constituting the sensible heat recovery type main heat exchanger 333 and the connection pipe 335b connected thereto. Therefore, as in Patent Document 1, the drain pipe 320 is connected to the connection pipe 335b connected to the sensible heat recovery type main heat exchanger 333, and the drain plug 302 is provided at the lower end of the drain pipe 320. If a drain plug 310 is provided on the bottom surface of the circulation pump 301, it is considered that the residual water in the circulation pipe 335 can be drained.

  However, when such a drain pipe 320 is provided, it is necessary to open not only the drain pipe 310 provided in the circulation pump 301 but also the drain pipe 302 provided in the drain pipe 320. There is a problem that the work of removing and checking the sealing performance is increased. In addition, the number of parts increases and the number of pipe connection points increases, leading to a problem of increased risk of water leakage.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bath water heater provided with a sensible heat recovery type main heat exchanger and a latent heat recovery type sub heat exchanger. In order to prevent freezing due to residual water, it is an object of the present invention to provide a bath hot water supply device that can reliably drain residual water in a circulation pipe with a simple structure.

The present invention comprises a bathtub,
A circulation pump having a drain plug;
A sensible heat recovery type main heat exchanger disposed above the bathtub and the circulation pump; and a latent heat recovery type sub heat exchanger disposed above the sensible heat recovery type main heat exchanger. A heat exchange section;
By the driving of the circulation pump, the water that has been preheated by the return pipe that rises from the outlet side of the bathtub toward the inlet side of the latent heat recovery type auxiliary heat exchanger, and the latent heat recovery type auxiliary heat exchanger, A first connection pipe that flows from the outlet side of the latent heat recovery type auxiliary heat exchanger toward the circulation pump, and preheated water that passes through the circulation pump passes from the circulation pump to the sensible heat recovery type main heat exchanger. The second connecting pipe rising toward the inlet side of the sensible heat and the hot water heated by the sensible heat recovery type main heat exchanger from the outlet side of the sensible heat recovery type main heat exchanger toward the inlet side of the bathtub It is a bath hot-water supply apparatus provided with the circulation pipe line which has the outgoing pipe which flows down.

  According to the above bath water heater, the bathtub water is returned from the bathtub by the circulation pump that circulates the bathtub water between the bathtub and the heat exchange part having the sensible heat recovery type main heat exchanger and the latent heat recovery type auxiliary heat exchanger. The pipe is raised and sent to the latent heat recovery type sub heat exchanger. After the latent heat is recovered by the latent heat recovery type sub heat exchanger and preheated, the first connection pipe is flowed down and sent to the circulation pump. Then, the preheated water rises from the circulation pump to the second connecting pipe and is sent to the sensible heat recovery type main heat exchanger, further heated by the sensible heat recovery type main heat exchanger, and then heated. The hot water flows down the pipe and reaches the bathtub. That is, the inlet side of the latent heat recovery type sub heat exchanger is connected to a bathtub positioned below the latent heat recovery type sub heat exchanger, and the outlet side of the latent heat recovery type sub heat exchanger is from the latent heat recovery type sub heat exchanger. The circulation pump located below and the first connection pipe are connected to each other, and the inlet side of the sensible heat recovery type main heat exchanger is located below the sensible heat recovery type main heat exchanger and the second connection pipe. Since the outlet side of the sensible heat recovery type main heat exchanger is connected to the bathtub located below the sensible heat recovery type main heat exchanger with the forward pipe, the circulation pump is stopped and When the circulation of water in the pipeline stops, the water in the latent heat recovery type secondary heat exchanger flows down the first connection pipe and the return pipe according to gravity, and the water in the sensible heat recovery type main heat exchanger is gravity. To flow down the second connecting pipe and the outgoing pipe. Therefore, by opening the drain plug provided in the circulation pump connected to the first connection pipe and the second connection pipe, the water remaining in the pipe constituting the circulation pipe is discharged. be able to.

The bath water heater further includes a hot water heat exchanger having a sensible heat recovery main heat exchanger for hot water heating and a sub-heat exchanger for latent heat recovery hot water for heating water from a water source,
The circulation pipe may be connected via a bypass pipe and a hot water supply pipe that supplies hot water heated by the hot water supply heat exchange section to a hot water supply destination.

  As described above, according to the bath hot water supply apparatus according to the present invention, even if the heat exchanging unit having both the latent heat recovery type sub heat exchanger and the sensible heat recovery type main heat exchanger is employed, the circulation pipe is provided. There is no need to provide a dedicated drain pipe or a drain plug to be provided. Therefore, the number of parts can be reduced to reduce the cost, and the risk of water leakage can be reduced. Moreover, since the draining work for preventing freezing can be performed by opening the drain plug provided in the circulation pump, it is possible to reduce the labor of the draining work and the confirmation work of the sealing performance of the drain plug.

It is a schematic block diagram which shows an example of the bath hot-water supply apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows an example of the hot water supply apparatus provided with the latent heat recovery type sub heat exchanger. It is a schematic block diagram which shows an example of the bath hot-water supply apparatus provided with the latent heat recovery type sub heat exchanger.

  Hereinafter, a hot water supply apparatus according to an embodiment of the present invention will be described with reference to FIG.

  This bath water heater has a hot water supply function for supplying hot water heated by the hot water supply heat exchange unit 50a to the hot water supply destination, a hot water filling function for supplying hot water heated by the hot water supply heat exchange unit 50a to the bathtub, and bath water. A reheating function of reheating and heating by the heat exchange unit 50b is provided.

  The hot water supply heat exchanging section 50a is provided above the hot water supply burner 51a and the hot water supply burner 51a, and the sensible heat recovery type main body for hot water supply that recovers the sensible heat in the combustion gas generated when the hot water supply burner 51a is burned. The heat exchanger 31 includes a hot water supply sensible heat recovery type main heat exchanger 31 and a hot water supply latent heat recovery type sub heat exchanger 32 that recovers the latent heat of the combustion gas. .

  When performing hot water supply operation, when the hot water tap at the hot water supply destination in the kitchen or bathroom is opened, water is passed through the water supply pipe 46, and the flow rate sensor 43 detects a flow rate exceeding the minimum operating flow rate passing through the water supply pipe 46. Then, the on-off valves 52a to 52c provided in the gas pipe 42 are opened, gas is supplied to the hot water supply burner 51a, and the hot water supply burner 51a is combusted.

  The water sent from the water supply pipe 46 to the hot water supply heat exchanger 50a by the combustion of the hot water supply burner 51a passes through the hot water supply latent heat recovery sub-heat exchanger 32 and the hot water supply sensible heat recovery main heat exchanger 31 in this order. To do. The passed water is preheated by recovering the latent heat in the combustion gas when passing through the hot water latent heat recovery type sub heat exchanger 32, and the preheated water is recovered from the subsequent sensible heat for hot water supply. By recovering sensible heat in the mold main heat exchanger 31, it is further heated to become hot water of a predetermined temperature, and hot water is discharged from each hot water supply destination through the hot water supply pipe 47.

  Then, the hot water tap is closed and the flow rate sensor 43 detects the stop of water flow, and at the same time, the on-off valves 52a to 52c are closed, whereby the gas supply to the hot water burner 51a is shut off, and the hot water burner 51a Combustion stops.

  A bypass pipe 26 is branchedly connected to the hot water supply pipe 47, and the bypass pipe 26 constitutes a circulation pipe 35 for replenishing the bath water through the pouring electromagnetic valve 27 and the flow rate sensor 15. Connected to piping.

  When performing a hot water filling operation, when a hot water filling operation switch (not shown) is turned on, the hot water solenoid valve 27 is opened and the bath water detected by the water level sensor 18 provided in the circulation line 35 is displayed. The hot water filling to the bathtub 30 is performed based on the water level of the water and the amount of the hot water filling detected by the flow sensor 15. In this hot water filling operation, as in the operation of the hot water supply operation, the hot water supply burner 51a is combusted and heated to pass through the hot water supply latent heat recovery sub-heat exchanger 32 and the hot water sensible heat recovery main heat exchanger 31 in order. Hot water heated to a predetermined temperature is supplied from the hot water supply pipe 47 to the bathtub 30 through the bypass pipe 26 and the circulation pipe 35.

  The heat exchanging part 50b for replenishing and heating the bath water is disposed above the bathtub 30 and the circulation pump 1, and disposed above the burner 51b and the burner 51b to burn the burner 51b. And a sensible heat recovery type main heat exchanger 33 for recovering sensible heat in the combustion gas generated at the time, and a sensible heat recovery type main heat exchanger 33 disposed above the sensible heat recovery type main heat exchanger 33 for recovering latent heat in the combustion gas. And a latent heat recovery type auxiliary heat exchanger. The heat exchange part 50b is accommodated in the outdoor heat source machine together with the above-described hot water supply heat exchange part 50a.

  The circulation pipe 35 is a recirculation circuit for circulating the bath water between the bathtub 30 and the heat exchange unit 50 b, and the latent heat recovery type sub-circuit from the outlet side of the circulation adapter 36 provided on the side wall of the bathtub 30. A return pipe 35a extending upward toward the inlet side of the pipe located at the lowermost stage of the heat exchanger 34, and the circulation pump 1 from the outlet side of the pipe located at the uppermost stage of the latent heat recovery sub heat exchanger 34. A first connection pipe 35b extending downward, a second connection pipe 35c extending upward from the circulation pump 1 toward the inlet side of the pipe located at the lowest stage of the sensible heat recovery type main heat exchanger 33, An outward pipe 35d extending downward from the outlet side of the pipe located at the uppermost stage of the heat recovery type main heat exchanger 33 toward the inlet side of the circulation adapter 36 of the bathtub 30 is provided. The return pipe 35a and the first connection pipe 35b connected to the pipe of the latent heat recovery type sub heat exchanger 34, the second connection pipe 35c connected to the pipe of the sensible heat recovery type main heat exchanger 33, and The forward pipe 35d is provided with an inclination on the circulation pump 1 and the tub 30 side so that residual water can easily flow from the pipes of the heat exchangers 33 and 34 during the water draining process described later. It may be connected to the piping of the vessels 33 and 34.

  The first connection pipe 35b and the second connection pipe 35c connecting the sensible heat recovery type main heat exchanger 33 and the latent heat recovery type sub heat exchanger 34 are connected via the circulation pump 1 provided with the drain plug 10 on the bottom surface. Connected. In the second connecting pipe 35c connecting the circulation pump 1 and the sensible heat recovery type main heat exchanger 33, it is detected that the water has flowed through the water level sensor 18 for detecting the water level of the bath water and the return pipe 35a. Then, a running water switch 17 which is turned on is disposed. Further, the forward pipe 35d is provided with a temperature sensor 16 for detecting the temperature of the hot water.

  In the present embodiment, the sensible heat recovery main heat exchanger 31 for hot water supply and the sensible heat recovery main heat exchanger 33 are plate-like fins that are erected on the outer peripheral surface of the pipe with a space therebetween. A heat exchanger that does not have fins is used as the latent heat recovery sub-heat exchanger 32 and the latent heat recovery sub-heat exchanger 34 for hot water supply, but these latent heat recovery-type sub heat exchanges are used. A heat exchanger having fins may be used for the vessels 32 and 34.

  A drain receiver 48 is provided below the latent heat recovery sub heat exchanger 32 and the latent heat recovery sub heat exchanger 34 for hot water supply, and the drain recovered by the drain receiver 48 is stored in the drain tank 13 to neutralize the drain. After being neutralized by the means, it is discharged from the discharge port 39 to the outside. Further, below the hot water supply burner 51a and the burner 51b, a combustion fan 5 for supplying combustion air to be mixed with the fuel gas is provided.

  When a reheating operation is performed, when a reheating switch (not shown) provided in a bathroom or the like is turned on, the circulation pump 1 is activated, and the bath water is transferred from the bath 30 to the latent heat recovery type sub heat exchange. The recirculation circuit in which the bath water circulates between the bathtub 30 and the heat exchange section 50b is formed by passing water in the order of the vessel 34, the circulation pump 1, and the sensible heat recovery type main heat exchanger 33. . When a predetermined amount of water flows through the circulation pipe 35, the water flow switch 17 is turned on, and the combustion fan 5 is activated. At the same time, the open / close valve 52d on the burner 51b side is opened, and the burner 51b is burned to catch up. Operation starts.

  By driving the circulation pump 1, the bath water rises from the outlet side of the circulation adapter 36 of the bathtub 30 toward the inlet side of the latent heat recovery type auxiliary heat exchanger 34 through the return pipe 35 a, and the latent heat recovery type auxiliary heat exchanger 34. After being preheated by recovering the latent heat, the first connecting pipe 35 b flows down from the outlet side of the latent heat recovery type sub heat exchanger 34 toward the circulation pump 1. The preheated water passing through the circulation pump 1 rises from the circulation pump 1 toward the inlet side of the sensible heat recovery type main heat exchanger 33 through the second connection pipe 35c, and the sensible heat recovery type main heat exchanger is obtained. 33. Then, the hot water further heated by recovering the sensible heat by the sensible heat recovery type main heat exchanger 33 passes through the outgoing pipe 35d from the outlet side of the sensible heat recovery type main heat exchanger 33 to the circulation adapter 36 of the bathtub 30. It flows down toward the entrance side. Such a chasing operation is continued until the temperature of the bath water reaches a predetermined set temperature. Thereby, bath water can be heated efficiently also in chasing operation, and energy saving can be achieved. When the temperature sensor 16 detects that the set temperature has been reached, the on-off valve 52d is closed and combustion of the burner 51b is stopped, and the driving of the combustion fan 5 and the circulation pump 1 is also stopped, and the reheating operation is completed. .

  By the way, in the said bath hot water supply apparatus, when temperature falls so that the water in the circulation line 35 freezes in winter, there exists a possibility that piping may be damaged by freezing of the water remaining in the circulation line 35. In such a case, it is necessary to carry out a draining operation for draining the residual water in the circulation pipe 35 so that the residual water does not freeze in the circulation pipe 35.

  In the bath water heater of the present embodiment, the drain pump 10 is provided in the circulation pump 1, and the drain plugs 24, 25 are provided in the return pipe 35a and the forward pipe 35d. These drain plugs 10, 24, 25 are opened. Then, the residual water in the circulation pipe 35 flows downward due to gravity. Specifically, the residual water in the upper pipe of the latent heat recovery type sub heat exchanger 34 flows down to the first connection pipe 35b side, is discharged to the outside from the drain plug 10 of the circulation pump 1, and in the lower pipe Residual water flows down the return pipe 35a and is discharged from the drain plug 24 to the outside. Similarly, the residual water in the upper pipe of the sensible heat recovery type main heat exchanger 33 flows down to the outgoing pipe 35d side, is discharged to the outside from the drain plug 25, and the residual water in the lower pipe is the second connecting pipe. It flows down on the 35c side and is discharged from the drain plug 10 of the circulation pump 1 to the outside. Thereby, all the residual water in the circulation pipe 35 is discharged.

  Thus, according to the bath hot water supply apparatus of the present embodiment, all the pipes constituting the circulation pipe 35 can be provided without providing a special drain pipe or a drain plug therefor only for discharging residual water. Since the residual water can be discharged from the pipe, it is possible to reliably prevent the inconvenience that the residual water is frozen in the pipe and the instrument is damaged. In addition, there is no special drainage pipe or drain plug for the purpose of draining residual water, which reduces the effort of draining and checking the sealing performance of the drain plug, and prevents freezing. Can be simplified.

  In the bath hot water supply apparatus of the present embodiment, the drain pipes 24 and 25 are provided in the return pipe 35a and the forward pipe 35d, but residual water is poured into the bathtub 30 without providing these drain pipes. It may be drained. In the above-described embodiment, the gas burner is adopted as the heat source. However, an oil combustion type or an electric type may be adopted instead of the gas. Further, these heat sources may be used in combination.

DESCRIPTION OF SYMBOLS 1 Circulation pump 10 Drain plug 30 Bathtub 35 Circulation line 35a Return pipe 35b 1st connection pipe 35c 2nd connection pipe 35d Outward pipe 33 Sensible heat recovery type main heat exchanger 34 Latent heat recovery type sub heat exchanger 50b Heat exchange part

Claims (2)

A bathtub,
A circulation pump having a drain plug;
A sensible heat recovery type main heat exchanger disposed above the bathtub and the circulation pump; and a latent heat recovery type sub heat exchanger disposed above the sensible heat recovery type main heat exchanger. A heat exchange section;
By the driving of the circulation pump, the water that has been preheated by the return pipe that rises from the outlet side of the bathtub toward the inlet side of the latent heat recovery type auxiliary heat exchanger, and the latent heat recovery type auxiliary heat exchanger, A first connection pipe that flows from the outlet side of the latent heat recovery type auxiliary heat exchanger toward the circulation pump, and preheated water that passes through the circulation pump passes from the circulation pump to the sensible heat recovery type main heat exchanger. The second connecting pipe rising toward the inlet side of the sensible heat and the hot water heated by the sensible heat recovery type main heat exchanger from the outlet side of the sensible heat recovery type main heat exchanger toward the inlet side of the bathtub A bath water heater comprising a circulation line having an outgoing pipe that flows down. A hot water supply heat exchanging unit having a sensible heat recovery type main heat exchanger for hot water supply for heating water from a water supply source and a latent heat recovery type auxiliary heat exchanger for hot water supply;
The hot water supply apparatus according to claim 1, wherein the circulation pipe is connected to a hot water supply pipe that supplies hot water heated by the heat exchange section for hot water supply to a hot water supply destination and a bypass pipe.

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