JP7267598B2 - Water heater - Google Patents

Description

In the present invention, a bypass pipe that bypasses the heat exchanger is connected between a water supply pipe and a hot water supply pipe that are connected to the heat exchanger, and water supplied from the water supply pipe is transferred between the heat exchanger side and the bypass pipe. The present invention relates to a water heater with a water distribution valve that distributes water to the sides.

In the water heater, a bypass pipe that bypasses the heat exchanger is connected between the water supply pipe and the hot water supply pipe that are connected to the heat exchanger, and a water distribution valve is provided in the bypass pipe, and the water is supplied by the operation of the water distribution valve. There is known one in which water is distributed to the heat exchanger side and the bypass pipe side (bypass side) (see, for example, Patent Document 1).
This water distribution valve is provided with a bypass-side first valve seat and a heat-exchanger-side second valve seat inside the valve body, and axially reciprocates between the two valve seats by motor drive. A valve body is provided. By changing the position of this valve element according to the incoming water temperature, the amount of incoming water, and the set temperature, the degree of opening of the first valve seat and the degree of opening of the second valve seat are adjusted to adjust the heat exchanger side. Distribute water to and from the bypass side. As a result, it is possible to prevent boiling due to an excessive amount of heating in the heat exchanger and to prevent the occurrence of drainage due to an insufficient amount of heating.

JP 2019-95160 A

In such a water distribution valve, in order to perform more flexible adjustment, there is a position in which the valve body is brought into contact with the first valve seat and the bypass side is fully closed (the heat exchanger side is fully open), and a position in which the second valve is fully closed. It is desirable to be able to move between a position in which the bypass side is fully opened (the heat exchanger side is fully closed) by contacting the valve seat of the heat exchanger.
However, in this case, when the hot water supply valve is opened in a state where the valve body is in contact with the second valve seat and the heat exchanger side is fully closed, the amount of water provided on the upstream side of the water distribution valve will increase. Since the water flow is detected by the sensor, the burner ignition control is performed as it is, and there is a risk that the heat exchanger will be heated without the water flow.
Also, when the residual water in the heat exchanger is drained, it is done through the water distribution valve. cannot be expelled, and freezing damage may occur in cold weather.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a water heater capable of preventing dry heating and freezing in a heat exchanger while ensuring an adjustment range in a water distribution valve.

In order to achieve the above object, the invention according to claim 1 has a bypass pipe that bypasses the heat exchanger and is connected between a water supply pipe and a hot water discharge pipe that are connected to the heat exchanger. A water heater equipped with a water distribution valve that distributes water supplied from a heat exchanger side and a bypass pipe side,
The water distribution valve includes a valve body having a water inlet, a bypass-side outlet, and a heat exchanger-side outlet. Inside the valve body, a distribution is provided in which a valve body connected to the water inlet is arranged so as to move back and forth. a passage portion, a bypass passage portion having an upstream side connected to the distribution passage portion and a downstream side connected to a bypass side outlet via a first valve seat closed at one moving end of the valve body; a heat exchanger passage portion connected upstream to the distribution passage portion and downstream connected to the heat exchanger side outlet via a second valve seat closed at the moving end of the heat exchanger passage portion;
A communicating portion is provided for communicating the distribution path portion and the heat exchanger path portion regardless of the forward/backward movement position of the valve body.
According to a second aspect of the present invention, in the configuration of claim 1, the distribution path portion is formed in a horizontal direction, and the heat exchanger path portion is a lateral path that is continuously extended from the distribution path portion in the horizontal direction. The communicating portion is characterized in that it connects the lower portions of the distribution channel portion and the horizontal channel portion.
According to a third aspect of the invention, in the configuration of the second aspect, the second valve seat is positioned inside a ring-shaped valve seat forming member that is inserted from the lateral passage portion side of the valve body and positioned in the distribution passage portion. It is characterized in that the communicating portion is formed by a notch formed in the outer periphery of the lower end of the valve seat forming member in the positioned state.

According to the first aspect of the invention, the water distribution valve is provided with the communicating portion that communicates the distribution path portion and the heat exchanger path portion regardless of the forward/backward movement position of the valve body. Even if the second valve seat is closed, the communicating portion can ensure the flow of water to the heat exchanger, and the remaining water in the heat exchanger can be drained through the communicating portion. Therefore, it is possible to prevent dry heating in the heat exchanger and reliably prevent freezing while ensuring an adjustment range in the water distribution valve.
According to the second aspect of the invention, in addition to the above effects, the communicating portion communicates the lower portions of the distribution path portion and the horizontal path portion with each other. can be discharged to
According to the third aspect of the invention, in addition to the above effects, the second valve seat is formed on the inner periphery of the ring-shaped valve seat forming member positioned in the distribution path portion, and the communication portion is positioned. Since the valve seat forming member is formed by a notch formed on the outer periphery of the lower end of the valve seat forming member in the state, the second valve seat and the gap can be easily formed at the same time as the valve seat forming member is assembled, and the gap is erroneously arranged in the notch. and misalignment will not occur.

It is a schematic circuit diagram of a bath water heater. It is a center longitudinal cross-sectional view of a water distribution valve. 3 is an enlarged cross-sectional view taken along line AA of FIG. 2; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Schematic configuration of bath water heater)
FIG. 1 is a schematic circuit diagram of a bath water heater 1, which is an example of a water heater.
In this bath water heater 1, a hot water supply combustion chamber 4 and a bath combustion chamber 5 are partitioned by a partition member 3 in an inner shell 2 housed in a housing (not shown). Hot water supply burners 6, 6, . . . and a bath burner 7 are provided. Further, each combustion chamber 4, 5 is provided with an ignition plug 8 and a flame rod 9, respectively. A combustion fan 10 for supplying combustion air to the burners 6 and 7 is provided in the lower portion of the inner barrel 2 .
A hot water supply primary heat exchanger 11 and a hot water supply secondary heat exchanger 12 through which combustion exhaust gas from the hot water supply burner 6 passes are provided in the upper part of the hot water supply combustion chamber 4 , and a bath burner 7 is provided in the upper part of the bath combustion chamber 5 . A bath primary heat exchanger 13 and a bath secondary heat exchanger 14 through which combustion exhaust gas passes are provided. Each secondary heat exchanger 12 , 14 is housed in an exhaust hood 15 provided on the upper part of the inner shell 2 . The exhaust hood 15 is formed with an exhaust port 16 through which combustion exhaust that has passed through the secondary heat exchangers 12 and 14 is discharged.

A gas inlet provided on the bottom surface of the housing is connected to a gas pipe 17 to which a gas pipe from the outside is connected. Branched from a gas pipe 17 are connected to the hot water supply burners 6 and the bath burners 7, respectively. 19 are provided respectively. The gas pipe 17 before branching is provided with a source gas electromagnetic valve 20 and a gas proportional valve 21 from the upstream side.

A water supply pipe 22 connected to a water inlet on the bottom surface of the housing is connected to the inlet of the heat absorption pipe of the hot water supply secondary heat exchanger 12 . The water supply pipe 22 includes, from the upstream side, a strainer 23 equipped with a drain plug, a hot water supply water quantity sensor 24 for detecting the quantity of water flowing through the water supply pipe 22, a hot water supply / water supply thermistor 25 for detecting the temperature of the water supply, and a water quantity control motor 26. and are provided. The outlet of the heat absorption tube is connected to the inlet of the heat transfer tube of the hot water supply primary heat exchanger 11, and the outlet of the heat transfer tube is connected to the hot water outlet 27 connected to the hot water outlet on the bottom surface of the housing. The hot water supply pipe 27 is provided with a hot water supply heat exchanger thermistor 28 for detecting the outlet temperature from the hot water supply primary heat exchanger 11, and a hot water supply heat exchanger thermistor 29 for detecting the temperature of the hot water discharged from the appliance on the downstream side thereof. A bypass pipe 30 that bypasses the hot water supply primary and secondary heat exchangers 11 and 12 is connected between the upstream side of the hot water supply/hot water supply thermistor 29 in the hot water supply pipe 27 and the downstream side of the water quantity control motor 26 in the water supply pipe 22 . , the bypass pipe 30 is provided with a water distribution valve 31 for controlling the bypass flow rate. Details of the water distribution valve 31 will be described later.
In this way, water from the water supply pipe 22 passes through the hot water supply secondary heat exchanger 12 and the hot water supply primary heat exchanger 11 in this order, exchanges heat with the combustion exhaust gas of the hot water supply burner 6, and is heated. A hot water supply circuit A for supplying hot water from 27 is formed.

On the other hand, the inlet of the heat absorption pipe of the bath secondary heat exchanger 14 is connected to a return pipe 35 that is connected to the bath return port on the bottom surface of the housing and has a drain plug. The bath return port is connected to a bathtub 37 via an external return pipe 36. - 特許庁Further, a pump 38 is provided downstream of the return pipe 35, a bath return thermistor 39 for detecting bath return temperature is provided upstream of the pump 38, and a bath water flow switch is provided downstream of the pump 38. 40 and a water level sensor 41 are provided.
The heat absorption tube outlet of the bath secondary heat exchanger 14 is connected to the heat transfer tube inlet of the bath primary heat exchanger 13, and the heat transfer tube outlet is connected to the bath outlet on the bottom surface of the housing by a feed pipe 42. Connected. The bath return port is connected to the bathtub 37 via an external pipe 43 . The going pipe 42 is provided with a bath going thermistor 44 for detecting the bath going temperature.
In this way, in the housing, hot water in the bathtub 37 passes through the return pipe 35 through the secondary bath heat exchanger 14 and the primary bath heat exchanger 13 in order by the operation of the pump 38, and exchanges heat with the combustion exhaust of the bath burner 7. After being heated, a bath circuit B (circulation circuit) returning to the bathtub 37 from the feed pipe 42 is formed.

A drop pipe 45 is connected between the outlet pipe 27 downstream of the bypass pipe 30 and the return pipe 35 upstream of the pump 38 . This drop pipe 45 is provided with a drop water electromagnetic valve 46 for opening and closing the drop pipe 45 and a bath water volume sensor 47 for detecting the amount of water flowing through the drop pipe 45 from the upstream side (hot water outlet pipe 27 side). . Further, two check valves 48, 48 are provided upstream and downstream of the bath water amount sensor 47, respectively. A valve 49 is connected. This gate valve 49 is connected to a drain pipe 50 connected to an overflow port provided on the bottom surface of the housing, and an introduction pipe 51 connected to the downstream side of the strainer 23 in the water supply pipe 22, so that the return pipe 35 When the internal pressure of the hot water in the dropping pipe 45 increased by the backflow of the hot water becomes higher than the back pressure applied from the introduction pipe 51, the hot water flowing back from the dropping pipe 45 is discharged to the overflow port through the drain pipe 50. - 特許庁

A neutralizer 55 for neutralizing drainage generated in the hot water supply secondary heat exchanger 12 and bath secondary heat exchanger 14 is provided in the housing. The neutralizer 55 is connected to a drain receiver 56 provided on the bottom surface of the exhaust hood 15 via a drain introduction pipe 57, and is also connected to the drain pipe 50 of the gate valve 49 via a drain discharge pipe 58. there is Further, the neutralizer 55 is provided with a water level electrode 59 for detecting the water level, and is also provided with a drain outlet 60 for discharging the drain from the bottom surface of the housing.
Reference numeral 65 denotes a controller that receives detection signals from thermistors, sensors, etc., and operates valves, etc., to control the temperature of discharged hot water, control the filling of hot water to the bathtub 37, etc.; 66, a hot water supply remote controller; and 67, a bath remote controller.

(Normal operation of bath water heater)
In this bath water heater 1, normal hot water supply and hot water filling are performed as follows.
First, in the hot water supply circuit A, the hot water supply valve of the external pipe connected to the hot water outlet is opened, water is supplied from the water supply pipe 22 into the appliance, and when the supply water amount sensor 24 detects the water supply, the controller 65 The combustion fan 10 is rotated for a predetermined period of time to discharge the combustion exhaust gas stored in the hot water supply combustion chamber 4 (prepurge). After that, the source gas solenoid valve 20 and each gas solenoid valve 19 of the gas pipe 17 are opened, and the gas proportional valve 21 is opened to a predetermined degree of opening to supply gas to the hot water supply burner 6 and to operate the igniter. Then, the hot water supply burner 6 is ignited by the ignition plug 8.
As a result, in the hot water supply secondary heat exchanger 12, water flowing from the water supply pipe 22 to the heat absorption pipe comes into contact with the combustion exhaust gas of the hot water supply burner 6, and latent heat is recovered. sensible heat is recovered by the hot water flowing into the hot water supply burner 6, and the hot water heated with high thermal efficiency is discharged from the hot water tap through the hot water discharge pipe 27 and the external pipe.

The controller 65 monitors the outlet temperature by the hot water supply heat exchanger thermistor 28 of the hot water supply pipe 27, and drives the water distribution valve 31 so that the outlet temperature can prevent the occurrence of drainage and overheating in the hot water supply primary heat exchanger 11. The flow rate (bypass rate) to the bypass pipe 30 is controlled so that the temperature is maintained within the range.
In addition, the hot water supply temperature is monitored by the hot water supply hot water supply thermistor 29, and the opening/closing control of each gas electromagnetic valve 19 and the opening of the gas proportional valve 21 are performed so that the hot water supply temperature reaches the set temperature indicated by the hot water supply remote controller 66 or the bath remote controller 67. In addition, the air amount is continuously changed by controlling the rotational speed of the combustion fan 10 .
When the hot water supply tap is closed, the controller 65 confirms that the signal from the hot water supply water quantity sensor 24 has stopped, closes the source gas solenoid valve 20 and the gas solenoid valve 19, extinguishes the hot water supply burner 6, and rotates the combustion fan 10 for a predetermined time ( post-purge).

On the other hand, when the automatic switch of the hot water supply remote controller 66 or the bath remote controller 67 is pressed, the controller 65 opens the drop water solenoid valve 46 of the drop pipe 45 to allow water to flow through the hot water supply primary and secondary heat exchangers 11 and 12. The hot water supply burner 6 is burned. Hot water from the hot water outlet pipe 27 is supplied to the bathtub 37 through the drop pipe 45 and the return pipe 35 . When the amount of water detected by the bath water amount sensor 47 provided in the drop pipe 45 reaches the set amount of water, the drop water electromagnetic valve 46 is closed to stop the water supply and the hot water supply burner 6 is extinguished.
Next, in the bath circuit B, the pump 38 is operated to circulate hot water between the bath primary/secondary heat exchangers 13 and 14 and the bathtub 37 . At this time, the bath return thermistor 39 and the bath return thermistor 44 monitor the temperature of the circulating hot water, and when a drop from the set temperature is confirmed, the controller 65 ignites the bath burner 7 and the combustion air is supplied by the combustion fan 10. supply. Therefore, the bath circulating water circulating between the bath primary and secondary heat exchangers 13, 14 and the bathtub 37 comes into contact with the combustion exhaust of the bath burner 7 when flowing through the heat absorption pipe of the bath secondary heat exchanger 14. Latent heat is recovered through the bath primary heat exchanger 13, and sensible heat is recovered by coming into contact with the combustion exhaust when flowing through the heat transfer tubes of the bath primary heat exchanger 13, and heated to the set temperature. When the set temperature is reached, the controller 65 stops the combustion of the bath burner 7 and the operation of the pump 38 .

(Explanation of water distribution valve)
2 is a sectional view of the water distribution valve 31. As shown in FIG. The water distribution valve 31 includes a valve body 70, a water inlet 71 to which a pipe on the upstream side of the water supply pipe 22 is connected, a distribution path section 72 into which water flows from the water inlet 71, It comprises a heat exchanger passage portion 73 branched to the heat exchanger 12 side and a bypass passage portion 74 branched to the bypass pipe 30 side.
The water inlet 71 projects downward from the valve body 70 , and the distribution path portion 72 is formed in a horizontal direction orthogonal to the water inlet 71 . For the sake of convenience, the bypass passage portion 74 side will be described as the front side, and the heat exchanger passage portion 73 side will be described as the rear side in the horizontal direction of FIG.

The heat exchanger path portion 73 includes a horizontal horizontal path portion 75 extending rearward from the rear end of the distribution path portion 72 and a vertical path portion 76 extending upward from the rear end of the horizontal path portion 75 . consists of A heat-exchanger-side outlet 77 is formed at the upper end of the vertical path portion 76 so as to protrude forward from the valve body 70 and is connected to a pipe on the downstream side of the water supply pipe 22 .
The bypass passage portion 74 is connected to the front end of the distribution passage portion 72 and extends forward, and the bypass side outlet 78 to which the bypass pipe 30 is connected is formed at the front end.
Further, a valve shaft 79 is arranged in the valve body 70 so as to straddle the distribution path portion 72 and the lateral path portion 75, and a support cylinder 80 is inserted and fixed from the rear end of the valve body 70 into the lateral path portion 75. It is supported so as to be movable back and forth. The valve shaft 79 is driven by a motor 81 connected to the rear end of the valve body 70 to move back and forth. A valve body 82 is integrally provided as a first valve portion 83 and a second valve portion 84 .

A first valve seat 85 consisting of a ring-shaped step formed on the inner surface of the valve body 70 is formed between the distribution passage portion 72 and the bypass passage portion 74 in front of the valve body 82 . A ring-shaped valve seat forming member 86 having a second valve seat 87 on its inner periphery is positioned and fixed behind the valve body 82 between the distribution channel portion 72 and the horizontal channel portion 75 . A first valve portion 83 of the advanced valve body 82 can be seated on the first valve seat 85 , and a second valve portion 84 of the retracted valve body 82 can be seated on the second valve seat 87 . ing.
As shown in FIG. 3, the valve seat forming member 86 engages a rib 89 formed on the upper inner surface of the valve body 70 with a recessed portion 88 formed on the upper end of the outer periphery. By fitting between the positioning protrusions 90 formed on the inner surface of each of the water inlets 71 and 90 , the water inlet 71 and the distribution path portion 72 are positioned in the front-rear direction at a position separating them from the horizontal path portion 75 . However, a notch 91 is partially provided on the outer periphery of the valve seat forming member 86, and the notch 91 is located at the lower end of the valve seat forming member 86 in the positioned state, thereby allowing the valve seat forming member A vertical gap 92 is formed between 86 and the inner surface of the valve body 70 .

Therefore, in the advanced position of the valve shaft 79 where the first valve portion 83 of the valve body 82 is seated on the first valve seat 85, the advanced valve body 82 moves the bypass path portion 74, as shown by the two-dot chain line in FIG. is fully closed, all of the water from the water inlet 71 flows from the distribution path portion 72 to the heat exchanger path portion 73 and flows through the hot water supply primary and secondary heat exchangers 11 and 12 .
On the other hand, in the retracted position of the valve shaft 79 where the second valve portion 84 of the valve body 82 is seated on the second valve seat 87, the retracted valve body 82 pushes the second valve seat 87, as shown by the solid line in FIG. and the second valve portion 84 are closed, but the water inlet 71 and the horizontal passage portion 75 are communicated with each other through the gap 92 below the valve seat forming member 86 . That is, even in the retracted position of the valve shaft 79 in which the second valve seat 87 is fully closed, the water from the water inlet 71 flows from the gap 92 through the heat exchanger path portion 73 to the primary and secondary heat exchangers 11, It will flow to 12.

In the bath water heater 1 configured as described above, when the hot water supply circuit A is used, the controller 65 drives the water distribution valve 31 as described above so that the outlet temperature is equal to that of the drain in the hot water supply primary heat exchanger 11. The flow rate (bypass rate) to the bypass pipe 30 is controlled so that the temperature is maintained within the temperature range capable of preventing generation and overheating. That is, the valve shaft 79 is reciprocated between the forward position and the retracted position, and the opening degree between the first valve portion 83 and the first valve seat 85 of the valve body 82 and the opening degree between the second valve portion 84 and the second valve portion 84 are adjusted. By changing the opening of the valve seat 87, the bypass rate is controlled.
Here, if the valve shaft 79 is in the retracted position and the second valve seat 87 is closed by the second valve portion 84 when hot water is started to be discharged, most of the water from the water inlet 71 is in the bypass passage portion 74. to the bypass pipe 30, but part of the water also flows from the heat exchanger path portion 73 to the hot water supply primary and secondary heat exchangers 11 and 12 through the gap 92, as indicated by solid line arrows in FIG. . Therefore, water flow can be ensured in both heat exchangers 11 and 12, and overheating in both heat exchangers 11 and 12 can be prevented. After that, when the valve body 82 moves forward by controlling the bypass rate, the excessively small water flow is eliminated.

On the other hand, when discharging residual water from both the heat exchangers 11 and 12 and the water supply pipe 22, even if the valve shaft 79 is in the retracted position and the second valve seat 87 is closed by the second valve portion 84, the strainer 23, the remaining water in both the heat exchangers 11 and 12 and the water supply pipe 22 on the downstream side of the water distribution valve 31 is released into the water distribution valve 31 as indicated by the dotted line arrow in FIG. The water flows from the heat exchanger path portion 73 to the distribution path portion 72 through the gap 92, flows from the water inlet 71 to the upstream side of the water supply pipe 22, and is discharged. Therefore, water can be reliably drained. In particular, since the gap 92 is positioned below the distribution path portion 72 and the heat exchanger path portion 73, water is less likely to stay in the valve body 70, and residual water in the water distribution valve 31 can be discharged reliably. .

Thus, in the bath water heater 1 of the above configuration, the water distribution valve 31 includes the valve body 70 having the water inlet 71, the bypass side outlet 78, and the heat exchanger side outlet 77. is connected to the water inlet 71 and includes a distribution passage portion 72 in which the valve body 82 is arranged so as to move back and forth; 72, and a heat exchanger path portion 73 connected to the distribution path portion 72 via a second valve seat 87 closed at the other moving end of the valve body 82. On the other hand, a gap 92 (communication portion) is provided to allow communication between the distribution path portion 72 and the heat exchanger path portion 73 regardless of the forward/backward movement position of the valve body 82 .
As a result, even if the second valve seat 87 is blocked by the valve body 82 , the gap 92 can ensure water flow to both the heat exchangers 11 and 12 . Also, even if the second valve seat 87 is closed, the remaining water in both the heat exchangers 11 and 12 can be drained through the gap 92 . Therefore, the first valve seat 85 and the second valve seat 87 can be fully closed by the valve body 82, and the adjustment width of the water distribution valve 31 can be secured, while the heat exchangers 11 and 12 can be boiled dry. It becomes possible to realize the prevention of freezing and reliable anti-freezing.

In particular, here, the distribution path portion 72 is formed in the horizontal direction, and the heat exchanger path portion 73 is formed including a horizontal path portion 75 extending from the distribution path portion 72 in the horizontal direction, Since the gap 92 allows the lower portions of the distribution path portion 72 and the horizontal path portion 75 to communicate with each other, residual water in the heat exchanger path portion 73 can be more reliably discharged.
Further, the second valve seat 87 is formed on the inner periphery of a ring-shaped valve seat forming member 86 that is inserted from the side of the lateral passage portion 75 of the valve body 70 and positioned in the distribution passage portion 72. Since it is formed by the notch 91 formed in the outer periphery of the lower end of the valve seat forming member 86 in the positioned state, the second valve seat 87 and the gap 92 can be easily formed at the same time as the valve seat forming member 86 is assembled. Become. In particular, the notch 91 is prevented from being misplaced or misaligned.

The shape of the notches provided in the valve seat forming member is not limited to the above-described form, and the number and shape of the notches may be appropriately changed, such as providing grooves at a plurality of locations. If there is no problem of residual water, it may be provided at the side end or the upper end of the valve seat forming member instead of the lower end.
The communicating portion is not limited to the case where the valve seat forming member is used. It is also possible to communicate with the heat exchanger path, or to form a notch or a through hole in the valve body for communicating the distribution path and the heat exchanger path in the closed state of the second valve seat. is.
Furthermore, the positions and structures of the water inlet, the heat exchanger side outlet, the bypass side outlet, and each path portion in the water distribution valve are not limited to the above-described forms. In the heat exchanger passage portion, one of the horizontal passage portion and the vertical passage portion may be omitted. It is also possible to arrange the valve shaft not only in the horizontal direction but also in the vertical direction so that the valve body can be moved up and down to open and close the vertically arranged valve seats.

On the other hand, it is not limited to the latent heat recovery type, and the hot water supply circuit and the bath circuit may not have a secondary heat exchanger.
Further, instead of the bath circuit, a heating circuit or the like may be provided in parallel with the hot water supply circuit, or a water heater having only a hot water supply circuit without such a circulation heating circuit may be used.

1 Bath water heater 2 Inner body 4 Hot water combustion chamber 5 Bath combustion chamber 6 Hot water burner 7 Bath burner 11 Primary heat exchanger for hot water 12 Hot water supply secondary heat exchanger 13 Bath primary heat exchanger 14 Bath secondary heat exchanger 15 Exhaust hood 17 Gas pipe 22 Water supply pipe 27 Hot water outlet pipe , 30... Bypass pipe, 35... Return pipe, 37... Bathtub, 42... Outgoing pipe, 45... Drop pipe, 65... Controller, 70... Valve body, 71... Water inlet, 72... Distribution route portion 73 Heat exchanger route portion 74 Bypass route portion 75 Horizontal route portion 76 Vertical route portion 77 Heat exchanger side outlet 78 Bypass side outlet 79... valve stem, 81... motor, 82... valve body, 83... first valve portion, 84... second valve portion, 85... first valve seat, 86... valve seat forming member, 87... Second valve seat, 91... Notch, 92... Gap, A... Hot water supply circuit, B... Bath circuit.

Claims (3)

A bypass pipe that bypasses the heat exchanger is connected between a water supply pipe and a hot water supply pipe that are connected to the heat exchanger, and the water supplied from the water supply pipe is transferred between the heat exchanger and the bypass. A water heater equipped with a water distribution valve that distributes to the pipe side,
The water distribution valve includes a valve body having a water inlet, a bypass-side outlet, and a heat exchanger-side outlet, and a valve body connected to the water inlet is arranged in the valve body so as to move forward and backward. and a bypass passage portion having an upstream side connected to the distribution passage portion and a downstream side connected to the bypass side outlet via a first valve seat closed at one moving end of the valve body. and a heat exchanger passage portion having an upstream side connected to the distribution passage portion and a downstream side connected to the heat exchanger side outlet via a second valve seat closed at the other moving end of the valve body. , is formed, while
A water heater, comprising: a communicating portion that allows communication between the distribution path portion and the heat exchanger path portion regardless of the advancing/retreating position of the valve body. The distribution path portion is formed in a horizontal direction, the heat exchanger path portion is formed to include a horizontal path portion extending continuously from the distribution path portion in the horizontal direction, and the communication portion is 2. The water heater according to claim 1, wherein lower portions of said distribution path portion and said horizontal path portion are communicated with each other. The second valve seat is formed on the inner periphery of a ring-shaped valve seat forming member that is inserted from the lateral passage portion side of the valve body and positioned in the distribution passage portion, and the communication portion is in the positioned state. 3. The water heater according to claim 2, wherein the notch is formed in the outer circumference of the lower end of the valve seat forming member.

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