JP6713882B2 - Hot water storage type water heater - Google Patents

Description

The present invention relates to a hot water storage type water heater.

2. Description of the Related Art Conventionally, there is known a hot water storage type water heater that heats supplied water by storing it in a tank provided with a heating means, and supplies the stored hot water to discharge hot water from a faucet (for example, Patent Document 1). In such a hot water storage type water heater, a drain pipe is provided in addition to the hot water supply pipe for supplying hot water from the tank to the faucet. The drainage pipe is provided for draining water in the tank at the time of maintenance and for the purpose of preventing freezing.

JP, 2005-78774, A

In the hot water storage type water heater of Patent Document 1, when draining water, it is necessary to arrange a container such as a basin below the drain plug to recover the water equivalent to the tank capacity, which is troublesome in draining work. It was In addition, during the general life of the product, the water is drained from the tank only a few times, for example, when the water heater itself is replaced at the end. As described above, the drain pipe needs to be provided with a component for a drain plug, although it is used less frequently, which is a problem in terms of cost.

In view of the above circumstances, it is an object of the present invention to provide a hot water storage water heater that facilitates draining water from the tank and that can reduce component costs.

The hot water storage type water heater according to the present invention is a tank for heating and storing hot water supplied from a water supply pipe, an expanded water drainage pipe for discharging expanded water generated in the tank, and water supply for the tank. Meanwhile, when the hot water in the tank is discharged and the hot water in the tank is replaced, a hot water replacement pipe that discharges the hot water in the tank and a tank provided below the tank, and water is not supplied to the tank A drainage pipe for discharging hot and cold water in the tank in a state, wherein the drainage pipe shares at least one part or all of the expansion water drainage pipe and the hot water replacement pipe, and the hot water replacement pipe Is provided below the tank, and the drain pipe is connected to the hot water replacement pipe upstream of the solenoid valve .

According to this invention, since the drain pipe shares at least one part or all of the expanded water drain pipe and the hot water replacement pipe, the drain pipe can be shared with at least one of the expanded water drain pipe and the hot water replacement pipe. The drainage pipe parts with less water consumption can be shared with other pipes. Therefore, it is possible to provide a hot water storage type hot water heater which can reduce manufacturing costs and can be easily maintained.

According to this invention, the downstream end of the drainage pipe can be shared with both the expanded water drainage pipe and the hot water replacement pipe, so that the parts cost of the drainage pipe can be further reduced. Further, it is possible to reduce the installation space for the drainage pipe under the tank.

According to this invention, the downstream end of the expansion water drain pipe and the relief valve are provided below the tank, the drain pipe is shared with the expansion water drain pipe from the upstream side of the relief valve, and the relief valve of the expansion water drain pipe is provided. By opening the valve, the hot and cold water in the tank can be discharged from the drainage pipe/expanded water drainage pipe, so that the cost of the drainage pipe parts can be kept low as compared with the case where a valve dedicated to the water drainage pipe is provided.

According to the present invention, since the electromagnetic valve of the hot water replacement pipe is provided below the tank, the electromagnetic valve can be shared as the valve of the drain pipe. Therefore, the hot water replacement pipe and the water drain pipe can be switched by controlling one solenoid valve. The cost of parts of the drainage pipe can be reduced as compared with the case where a valve dedicated to the drainage pipe is provided.

In the hot water storage water heater according to the present invention, the operation of the heating unit provided in the tank may be stopped in accordance with the control of the electromagnetic valve for draining water in the drain pipe.

According to the present invention, it is possible to prevent the heating unit in the tank from operating after draining the water in the tank, and to prevent the empty heating.

According to the hot water storage type water heater of the present invention, it is possible to provide a hot water storage type water heater in which water can be easily drained from the tank and the cost of parts can be reduced.

It is a perspective view of the hot water storage type water heater which concerns on one Embodiment of this invention. It is a front view of the inside of the hot water storage type water heater concerning one embodiment of the present invention. It is a figure which shows the internal structure of the hot water storage type water heater which concerns on one Embodiment of this invention. It is an exploded perspective view of a water supply pipe joint of one embodiment of the present invention. It is a fragmentary sectional view of the tank upper part of one embodiment of the present invention. It is a bottom view of the hot water storage type water heater which concerns on one Embodiment of this invention. It is a figure which shows the mounting aspect of the hot water storage type water heater which concerns on one Embodiment of this invention. It is a figure which shows the internal structure of the hot water storage type water heater of the 1st modification of one Embodiment of this invention. It is a flowchart at the time of the water removal process of the hot water storage type water heater which concerns on one Embodiment of this invention.

A hot water storage water heater according to an embodiment of the present invention will be described. FIG. 1 is a perspective view of a hot water storage water heater 1 according to the present embodiment. The hot water storage type water heater 1 according to the present embodiment is used by being fixed to a wall surface above the sink 100. The hot water storage type water heater 1 is connected to the mixed water faucet 5 and the drain port 9 provided on the sink 100 via a pipe in the wall.

FIG. 2 is a front view of the inside of the hot water storage water heater 1. FIG. 3 is a diagram showing an internal configuration of the hot water storage water heater 1. As shown in FIG. 2, a hot water storage type water heater 1 according to the present embodiment is provided with a water supply pipe 2, a tank 3, a hot water supply pipe 4, a hot water replacement pipe/air bleeding pipe 6, an expanded water drainage pipe/drainage pipe. 8 and a power cord 10, which are fixed to a base 11.

The water supply pipe 2 has an upstream end connected to the water supply plug 20 and a downstream end connected to the tank 3. The water supply pipe 2 is provided with a filter 21, a check valve 22, a pressure reducing valve 23, a thermistor 24, and a flow sensor 25 in this order from upstream to downstream.

FIG. 4 shows an exploded perspective view of the water supply pipe joint 27 attached to the water supply pipe 2. As shown in FIG. 4, the filter 21 is attached to the water supply pipe joint 27. The filter 21 is provided between the water tap 20 and the pressure reducing valve 23 to prevent dust from being caught in the pressure reducing valve 23. The water supply pipe joint 27 may be attached inside the cover of the water heater 1, or may be attached by connecting to the water heater water supply port 201 that connects the water supply pipe 2 to the water heater 1.

The water supply pipe joint 27 has a substantially tubular joint body 271 that includes an upstream connection port 272, a downstream connection port 273, and a filter mounting port 274. The upstream connection port 272 is opened at one end of the joint body 271 in the longitudinal axis direction, and the filter attachment port 274 is opened at the other end. The downstream connection port 273 projects from the outer peripheral surface of the joint body 271 in the vicinity of the filter mounting port 274 and opens in a direction orthogonal to the upstream connection port 272. The upstream connection port 272 is connected to the water supply pipe 2 on the water tap 20 side, and the downstream connection port 273 is connected to the water supply pipe 2 on the tank 3 side. The filter fixing portion 28 is inserted and fixed in the filter attachment port 274. The filter fixing portion 28 includes a tubular filter 21 having a size that can be inserted into the joint body 271. When the filter fixing portion 28 is inserted and fixed inside the joint main body 271, the filter 21 covers the downstream side connection port 273 on the inner peripheral surface side of the joint main body 271. When the water supplied from the water supply pipe 2 passes through the water supply pipe joint 27, the filter 21 removes dust in the water. The water supply pipe joint 27 can be configured by a component common to the water supply plug 20, and can be used as a water supply plug by attaching an openable/closable plug body to the filter fixing portion 28.

The check valve 22, the pressure reducing valve 23, the thermistor 24, and the flow sensor 25 are known members. Water that has passed through the filter 21 passes through the check valve 22, is decompressed by the decompression valve 23, and flows into the tank 3. At this time, the thermistor 24 detects the temperature of the water supply pipe 2, and the flow sensor 25 detects the amount of flowing water in the water supply pipe 2.

The tank 3 has a water supply port formed at the lower end, and the downstream end of the water supply pipe 2 is connected to the water supply port. A heating unit 31 and two thermistors 32 and 33 are provided inside the tank 3. The heating unit 31 is a heating wire and heats the water in the tank 3. The inside of the tank 3 is a closed tank that is kept full of water. In the tank 3, the water temperature at the lower part is low, and the water temperature from the vicinity of the heating part 31 to the upper part is high. Two thermistors 32 and 33 provided in the upper and lower parts of the tank 3 detect the water temperatures of the upper and lower parts of the tank 3, and a controller (not shown) controls the energization amount of the heating part.

FIG. 5 is a partial cross-sectional view of the upper portion of the tank 3. One hot water supply opening 35 is formed in the center of the upper end of the tank 3. The hot water supply pipe 4 is connected to the hot water supply opening 35 through a connection joint 34 inserted in the hot water supply opening 35. The connection joint 34 is a one-piece component integrally formed with a hot water outlet 342 and an air vent passage 340 inside. The hot water discharge passage 342 and the air bleeding passage 340 are arranged so as to extend in parallel on the upstream side provided in the tank 3 and to extend in the opposite direction at the same height on the downstream side protruding above the tank 3. Is bent.

The hot water supply pipe 4 is connected to the downstream end of the hot water outlet 342. As shown in FIG. 2, the hot water supply pipe 4 extends in the radial direction of the tank 3 at a position slightly separated from the upper surface of the tank 3, then bends downward and extends downward along the outer peripheral surface of the tank 3. Has been formed. The downstream end of the hot water supply pipe 4 is connected to the mixed tap 5 provided above the sink 100. The water supply pipe 2 is also connected to the mixed water faucet 5.

The air vent pipe 6 is connected to the downstream end of the air vent passage 340. The air bleeding pipe 6 is connected to an opening on the downstream side of the air bleeding passage 340, extends to the side opposite to the hot water supply pipe 4, then curves and extends substantially parallel to the hot water supply pipe 4, and is slightly separated from the upper surface of the tank 3. After extending in the radial direction of the tank 3 at this position, the tank 3 is bent downward and extends downward along the outer peripheral surface of the tank 3. The air vent pipe 6 is a pipe line for deaerating air generated by heating in the tank 3 in order to prevent disturbance of water discharge due to mixing of bubbles during hot water supply, and is made of the same pipe as the hot water replacement pipe 6.

The hot water replacement pipe 6 is a pipe line for discharging hot water in the tank 3 when the hot water in the tank 3 is replaced by replacing the hot water in the tank 3 while supplying water to the tank 3. The hot water replacement pipe 6 is made of the same pipe as the air bleeding pipe 6.

As shown in FIG. 3, the upstream end of the air vent pipe (hot water replacement pipe) 6 is connected to the upper portion of the tank 3 via the air vent passage 340 of the connection joint, and the downstream end is connected to the drain port 9. A known check valve 61, a solenoid valve 70, and a thermistor 71 are provided between the upstream end and the downstream end of the air bleeding pipe (hot water replacement pipe) 6. A branch portion of the water supply pipe 2 is provided at a position between the thermistor 24 and the flow sensor 25 of the water supply pipe 2, and the branched water supply pipe 2 is connected to the check valve 61 of the air bleeder pipe (hot water replacement pipe) 6 and the electromagnetic valve. It is connected to the valve 70.

The expansion water drain pipe 8 is a pipe line for discharging the expansion water generated in the tank 3 to the outside when the temperature inside the sealed tank 3 becomes higher than a predetermined temperature. The expansion water drain pipe 8 branches from the water supply pipe 2 below the tank 3 and extends to the drain port 9. The expansion water drain pipe 8 includes a relief valve 80 between a branch portion from the water supply pipe 2 and the drain port 9. The relief valve 80 is a valve that opens when the internal pressure on the tank side increases due to the expanded water generated in the tank 3 and discharges the expanded water to the drain port 9. The expanded water drainage pipe 8 is connected to the air vent pipe/hot water exchange pipe 6 on the downstream side of the thermistor 71 of the hot water exchange pipe 6, and shares the drain port 9 of the air vent pipe/hot water exchange pipe 6. The expansion water drain pipe 8 is composed of the same pipe as the drain pipe 8. The drainage pipe 8 is a pipe provided below the tank 3 for discharging hot and cold water in the tank 3 in a state where water is not supplied to the tank 3. Since the water drain pipe 8 including the relief valve 80 is arranged below the tank 3, when the relief valve 80 is opened, the water stored in the tank 3 flows out and drains from the drain port 9. Is configured to be. Therefore, if the relief valve 80 is forcibly opened with the water tap 20 closed, all the water in the tank 3 can be drained. In addition, the lower side of the tank 3 refers to a position lower than the bottom surface of the tank 3, and in addition to the region immediately below the tank 3, as shown in FIG. Including low position.

FIG. 6 is a bottom view of the hot water storage water heater 1. In this embodiment, the drain pipe 8 is connected to the air drain pipe (hot water replacement pipe) 6 and shares one drain port 9. Therefore, as shown in FIG. 6, on the bottom surface of the base 11 of the hot water storage type water heater 1, the pipe serving as the air vent pipe 6, the hot water replacement pipe 6, and the water drain pipe 8, the water supply pipe 2, and the hot water supply pipe 4 are provided. Only three tubes are provided.

The hot water storage water heater 1 further includes a control unit (not shown) and an operation panel 16 connected to the control unit. The operation panel 16 includes a display unit 17 and a plurality of operation buttons 18. The display unit 17 is configured to be able to display operation information such as the operating status of the hot water storage water heater 1 and the water temperature. The operation button 18 is used when performing various input operations such as turning on the power of the hot water storage water heater 1 and setting hot water supply.

FIG. 7: is a figure which shows the attachment mode of the hot water storage type water heater 1. As shown in FIG. As shown in FIG. 7, a locking hole 14 is formed in the back surface of the base 11. The base 11 of the hot water storage type water heater 1 is attached to the wall surface by locking the locking hole 14 to the locking member 15 which is previously attached to the wall surface to which the hot water storage type water heater 1 is attached. After the base 11 is locked and fixed to the wall surface, the upper portion of the base 11 is covered with the upper cover 12, and the lower side of the bottom surface is covered with the lower cover 13. The upper cover 12 and the lower cover 13 are members having a U-shaped cross section, which is composed of three surfaces that form a front surface and both side surfaces. The upper cover 12 is arranged so as to cover from the front side of the base 11 toward the wall surface side, and in a state where both side surfaces are locked to the base 11, screws are fixed to screw holes provided at the lower end of the front surface. , Fixed to the base 11. After fixing the upper cover 12, the lower cover 13 is pushed in from the front side toward the wall surface side while being locked to the lower edge of the upper cover 12, and the bottom surface of the fixing portion protruding downward from the upper cover 12 is made up from below. Secure with screws.

Next, the operation of the hot water storage type water heater 1 will be described. The tank 3 is filled with water from which the dust has been removed from the water supply pipe 2 through the filter 21. The water in the tank 3 is heated when the heating unit 31 is energized, and the water in the upper part of the tank 3 has a relatively high temperature. The thermistors 32 and 33 provided at the upper and lower parts of the tank 3 detect the water temperature in the tank 3, and the control unit controls the energization state of the heating unit 31 so that the hot water supply state is maintained.

When the mixed faucet 5 is opened, hot water flows into the hot water supply pipe 4 through the hot water supply passage 342 of the connection joint 34 above the tank 3. Since the branch water supply pipe 26 branched from the water supply pipe 2 is connected to the mixed water faucet 5, a part of the water supply is diverted from the water supply pipe 2 and the hot water and the water merge to form hot water from the mixed water faucet 5. Is leaked. Water is supplied from the water supply pipe 2 into the tank 3 in accordance with the amount of hot water flowing through the hot water supply pipe 4. When the mixed faucet 5 is closed again, the flow of hot water in the hot water supply pipe 4 is stopped, and the inflow of water from the water supply pipe 2 into the tank 3 is also stopped.

When heating the water in the tank 3, bubbles (air) are generated in the upper part of the tank 3 when the temperature in the sealed tank 3 becomes higher than a predetermined temperature. If the faucet of the faucet is opened with the air accumulated in the upper part of the tank 3, the air may be mixed into the spouted water to impair the rectifying property, which may disturb the spouted water. In order to prevent such disturbance of water discharge, air bleeding is performed. Specifically, when the thermistor 33 provided in the upper portion of the tank 3 detects a temperature equal to or higher than a predetermined value, the control unit determines that the dissolved air in the tank 3 has begun to vaporize, and controls to open the solenoid valve 70. Is done. By opening the solenoid valve 70, the air in the tank 3 passes through the check valve 61 provided in the air vent pipe 6 communicating with the tank 3 through the air vent passage 340 of the connection joint 34. The air is discharged from a drain port 9 provided at the downstream end of the air bleeding pipe 6.

The expanded water is generated when the volume of water in the tank 3 expands when the water in the tank 3 is heated. The volume of the expanded water that exceeds the set pressure of the relief valve 80 is discharged from the drain port 9 as needed. Since the expansion water drain pipe 8 is branched from the water supply pipe 2, the temperature of the expansion water discharged from the drain port 9 is unlikely to rise. However, the hot water in the heated tank may drop toward the water supply side by discharging the expanded water, and the expanded water temperature may gradually rise. Therefore, the temperature inside the tank 3 is detected by the thermistors 32 and 33, and when the temperature becomes equal to or higher than a predetermined temperature (for example, 84 degrees), the control unit performs control to increase the frequency of opening the solenoid valve 70. Since the water is discharged from the branch water supply pipe 29 by opening the electromagnetic valve 70, the downstream side of the expansion water drain pipe 8 can be cooled. Further, since the water is also supplied into the tank 3, the hot water in the tank 3 is pushed down to the water supply side, so that the discharge temperature of the expanded water can be lowered. The electromagnetic valve 70 is opened at a certain frequency for bleeding air until the inside of the tank 3 reaches a predetermined temperature. However, after the temperature exceeds a predetermined temperature, the purpose of cooling the expansion water drain pipe 8 is added. The control for increasing the opening frequency of the solenoid valve 70 is performed.

Next, in the hot water storage type water heater 1, a sufficient amount of hot water is secured in the tank 3 in order to keep the hot water supplyable state. However, the hot water storage hot water heater 1 may be used less frequently, for example, at night or on holidays, and hot water in the tank 3 may be stored without being consumed for a long time. In such a case, in order to maintain the sanitary condition of the hot water, the hot water replacement process of discharging the hot water in the tank 3 is performed independently of the operation of the mixed faucet 5.

The hot water replacement process is performed by the control unit when a predetermined condition is satisfied based on the nonuse time of the mixed faucet 5 and the flowing water amount detected by the flow sensor 25. When the predetermined condition of the hot water replacement process is satisfied, the solenoid valve 70 is opened by the control of the control unit. When the solenoid valve 70 is opened, hot water flows through the hot water replacement pipe 6 and is discharged from the drain port 9. At this time, since the water in the water supply pipe 2 flows through the branch water supply pipe 29 as in the case of draining air, the temperature of the hot water is lowered and the water is discharged from the drain port 9 as hot water.

The hot water replacement process is performed by the controller when the amount of flowing water in the water supply pipe 2 detected by the flow sensor 25 reaches a predetermined amount, or when the temperature detected by the thermistor 33 in the tank 3 falls below a predetermined value. The process of closing the valve 70 is performed and the process ends.

On the other hand, at the time of maintenance or replacement of the hot water storage water heater 1, a water draining process is performed to drain all the water in the tank 3. In order to prevent the inside of the tank 3 from being heated, it is necessary to stop the operation of the heating unit by turning off the power source in advance during the water draining process. When performing the drainage process, the user manually closes the water tap 20 and operates the relief valve 80 to open the valve. Since the drain pipe 8 is located below the tank 3, it is naturally drained from the drain port 9 by the opening operation of the relief valve 80.

According to the hot water storage water heater 1 according to the present embodiment, the drain pipe 8 is formed of the same pipe as the expanded water drain pipe 8, so that the drain pipe 8 that is rarely used can be shared with the expanded water drain pipe 8. Therefore, it is possible to provide the hot-water storage hot water heater 1 which can reduce the manufacturing cost and can be easily maintained. Further, the installation space of the drain pipe 8 can be reduced below the tank 3.

According to the hot water storage type water heater 1 according to the present embodiment, the downstream end of the expansion water drain pipe 8 and the relief valve 80 are provided below the tank 3, and the expansion water drain pipe 8 can be used as the drain pipe 8. Hot water in the tank 3 can be discharged through the drain port 9 by opening the valve 80. Therefore, the cost of parts can be kept low as compared with the case where a drainage port dedicated to the drain pipe is provided. Further, since the drainage in the tank 3 can be drained from the drainage port 9, the drainage collection work becomes easier as compared with the case where the drainage is collected by the conventional washbasin.

According to the hot water storage water heater 1 according to the present embodiment, only the three pipes of the water supply pipe 2, the hot water supply pipe 4, and the drain pipe are provided on the bottom surface of the base 11 of the hot water storage water heater 1. That is, the expansion water drain pipe 8, the water drain pipe 8, the air bleed pipe 6, and the hot water replacement pipe 6 merge in front of the drain port 9 to form a single drain pipe, so that the hot water storage water heater 1 The piping work during installation work is reduced.

In the present embodiment, the upper cover 12 is arranged from the front side toward the wall surface side, and after being fixed, the lower cover 13 is pushed toward the wall surface side from the front side while being locked to the lower end edge of the upper cover 12, and the bottom surface is pressed from below. Since it is fixed with a decorative screw, it can be easily installed regardless of the installation location. That is, the hot water storage water heater 1 can be installed even when the hot water storage water heater 1 is installed at a corner of the room and one side surface is close to the wall surface.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range not departing from the gist of the present invention.
Further, the constituent elements shown in each of the above-described embodiments and each modification can be appropriately combined and configured.

In the above embodiment, an example in which only the mixed water faucet 5 is provided as the hot water supply faucet is shown, but a hot water faucet for discharging only hot water may be provided separately. In this case, a branch passage of the hot water supply pipe 4 may be provided to connect with the hot water faucet.

In the present embodiment, the entire expansion water drainage pipe is common to the water drainage pipe, but it may be merged on the downstream side and the drainage port may be common. In this case, the upstream end of the expansion water drain pipe upstream of the confluence position with the drain pipe may be higher than the bottom surface of the tank, so that the upstream end may be connected to the tank upper part. In the case of merging on the downstream side of the relief valve, another valve for draining water may be provided. It suffices if all drainage pipe paths from the tank to the drain port are below the tank.

In the present embodiment, an example is shown in which the expanded water drain pipe 8, the water drain pipe 8, the air vent pipe 6, and the hot water replacement pipe 6 are connected to the same drain port 9. However, the drainage pipe may have a configuration in which the drainage port is shared with at least one of the air removal pipe, the hot water replacement pipe, and the expansion water drainage pipe. For example, a configuration like the modification shown in FIG. May be

A first modified example of the above embodiment is shown in FIG. The hot water storage type water heater 1A of the modified example shown in FIG. 8 is different from the above embodiment in that the downstream side portion of the hot water replacement pipe 6 is shared as the water drainage pipe 8A. In the following description, the same components as those already described will be denoted by the same reference numerals and redundant description will be omitted.

In the hot water storage water heater 1A, the downstream portion of the water supply pipe 2, the branch water supply pipe 29, and the downstream portion of the hot water replacement pipe 6 are used as the drain pipe 8A. The downstream side portion of the water supply pipe 2 is a portion between the connecting portion between the water supply pipe 2 and the tank 3 and the branch portion between the branch water supply pipe 29. The downstream side portion of the hot water replacement pipe 6 is a portion of the hot water replacement pipe 6 from a connection portion between the branch water supply pipe 29 and the hot water replacement pipe 6 to the drainage port 9. The branch water supply pipe 29 is provided with a check valve 291. Since the branch water supply pipe 29 is connected between the check valve 61 of the hot water replacement pipe 6 and the solenoid valve 70, the solenoid valve 70 functions as a drainage valve like the relief valve 80 in the first embodiment. It has the function of.

FIG. 9 shows a flowchart of the water removal process in the control unit of this modification. That is, when performing the drainage process, the user manually closes the water tap 20 and then performs a drainage start operation using the operation button 18 (step S1). At this time, the control unit determines whether or not the heating unit 31 is energized (step S2). When the heating unit 31 is energized (YES), the control unit stops energizing the heating unit 31 (step S3), and then the control unit opens the electromagnetic valve 70 (step S4). On the other hand, when the heating unit 31 is not energized (NO), the control unit proceeds to step S4 to open the solenoid valve 70. Since the solenoid valve 70 is provided below the tank 3 and the water tap 20 is closed, when the solenoid valve 79 is opened, the water in the tank 3 is the upstream side portion of the water supply pipe 2, the branch water supply. The water flows through the pipe 29 and the downstream portion of the hot water replacement pipe 6, and is naturally drained from the drain port 9 to perform a drainage process.

Next, when the water draining process is completed, the user operates the operation button 18 of the operation panel 16 to input the end of the water draining process (step S5). Subsequently, the control unit performs the valve closing process of the electromagnetic valve 70 (step S6), and thereafter, the power source of the hot water storage water heater 1 is turned off by the control unit (step S7), and the water draining process ends.

According to the hot water storage type water heater 1A according to the present modification, the electromagnetic valve 70 of the hot water replacement pipe 6 is provided below the tank 3, so that the electromagnetic valve 70 can be shared as the valve of the drain pipe 8. Therefore, the hot water replacement pipe 6 and the water drain pipe 8A can be switched by controlling one solenoid valve 70. The cost of parts of the drainage pipe can be reduced as compared with the case where a valve dedicated to the drainage pipe is provided. According to the hot water storage type water heater 1 according to the present embodiment, the operation of the heating unit 31 is stopped by the control unit during the water removal process, so that the heating unit 31 in the tank 3 operates after draining the water in the tank 3. It is possible to prevent this from happening, and to prevent empty heating.

In this modification, the expansion water drainage path may be provided separately. The expansion water drainage route may be separately provided and only the drainage port may be shared with other pipes, or the drainage port for the expansion water drainage route may be independently provided. By connecting the drainage pipe to at least one of the expansion water drainage pipe and the hot water replacement pipe, a part of the drainage pipe that is less frequently used is shared, and the number of parts can be reduced.

In the above embodiment, an example in which the connection joint 43 including the hot water outlet 342 and the air bleeding passage 340 is used and which is integrally formed is shown. However, the connection joint 43 of the present embodiment is not an essential configuration, and a hot water supply pipe The connection joint for 4 and the connection joint for the air vent pipe (hot water replacement pipe) may be separately provided.

In the above embodiment, an example of the hot water storage water heater 1 fixed to the wall is shown. However, if there is a space where a drainage pipe can be arranged below the tank, it can be used as a hot water storage water heater placed on the floor. Can be used. In addition, although an example in which the drain port 9 is provided on the sink to drain the water to the sink has been shown, the drain port 9 may be drained directly to the drain pipe.

1 Hot water storage type water heater 2 Water supply pipe 3 Tank 4 Hot water supply pipe 6 Hot water replacement pipe, air bleeder pipe 8 Drainage pipe, expanded water drainage pipe 9 Drainage outlet

Claims (2)

A tank that heats the water supplied from the water supply pipe and stores it
An expanded water drainage pipe for discharging expanded water generated in the tank,
A hot water replacement pipe for discharging hot water in the tank when the hot water in the tank is discharged and hot water in the tank is replaced while supplying water to the tank,
A drain pipe provided below the tank for discharging hot water from the tank in a state where water is not supplied to the tank;
Equipped with
The drainage pipe shares a part or all of at least one of the expanded water drainage pipe and the hot water replacement pipe ,
An electromagnetic valve for opening and closing the hot water replacement pipe is provided below the tank,
A hot water storage type water heater characterized in that the water drain pipe is connected to the hot water replacement pipe upstream of the solenoid valve . The hot water storage water heater according to claim 1, wherein the operation of the heating unit provided in the tank is stopped in accordance with the control of the electromagnetic valve for draining water in the drain pipe.

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