JP3989164B2 - Water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water heater that heats water with a heater such as a gas burner and supplies hot water to a kitchen or a bath.
[0002]
[Prior art]
BACKGROUND ART Gas water heaters that heat water with gas combustion heat to form hot water and supply it to hot water taps, bathtubs, indoor heating devices, and the like are widely used in general households. The simplest one is a completely manual type, in which a man ignites a seed fire by manually operating an ignition device, and after checking the ignition visually, the hot water tap is opened. When the water tap is opened, the flow of water is confirmed by the water volume sensor or the water pressure sensor, the gas shut-off valve is opened, the gas is supplied to the burner, and the gas is ignited by the fire from the seed fire. Thus, the water in the heat exchanger is heated and supplied as hot water from a hot water tap.
[0003]
However, in recent years, hot water heater systems have become more sophisticated, and automatic control water heaters that use hot water temperature control, combustion control, and safety confirmation by control devices in response to inputs from various sensors have come to be used. It is coming. An example is shown in FIG.
[0004]
A gas burner 12 and a heat exchanger 13 are provided in the water heater main body 11, and the water in the heat exchanger 13 is heated by the combustion heat of the gas burner 12. When the hot water tap is opened, water is supplied from the water supply system to the heat exchanger 13 through the water filter 14. Since the amount of water is detected by the water amount sensor 15, a control device (not shown) in the electrical board opens the original gas solenoid valve 16, applies a voltage to the spark plug 17, and gas is generated by the spark. Ignite. Thereby, the gas from the combustion pipe 18 is combusted, and the water in the heat exchanger 13 is heated.
[0005]
The water supply flow rate is controlled by the water amount adjustment valve 19, and the hot water supply temperature is detected by the hot water thermistor 20 to control the opening degree of the bypass water amount adjustment valve 21 and the opening degree of the gas proportional valve 22. To maintain the target temperature. For this control, the temperature of the feed water detected by the incoming water thermistor 23 and the temperature of the hot water at the outlet of the heat exchanger 13 detected by the can water thermistor 24 are simultaneously used. When the target hot water temperature is greatly different or the amount of water supply is greatly different and cannot be controlled by the opening degree of the bypass water amount adjusting valve 21 or the gas proportional valve 22, the gas burner is opened and closed by opening and closing the capacity switching gas electromagnetic valve 25. It responds by changing the combustion capacity of
[0006]
Combustion air is supplied from the combustion fan 26 to the gas burner 12. In order to detect whether or not combustion air is supplied, a rotation speed sensor 27 of the combustion fan 26 is provided. In addition to this, the rotation speed sensor 27 is used to control the rotation speed of the combustion fan 26 so as to supply an air volume corresponding to the gas volume.
[0007]
As a safety device, an overheat prevention sensor 28 for detecting overheating of the water heater main body, an overpressure prevention safety device 29 for preventing overheat in the heat exchanger 13 and the hot water supply pipe, and preventing it from draining, in the heat exchanger 13, an afterfire safety device 30 for detecting overheating of the heat exchanger 13 due to afterfire, a leakage safety device 31 for detecting leakage, a flame detector 32 for detecting gas combustion flame, and the like are provided.
[0008]
FIG. 4 shows a schematic flowchart describing the main operation of the control device in the electrical board. When a human turns on the power in step S01, it is checked in step S02 whether the leakage safety device is inoperative. Since it is normal when it is inoperative, it is possible to shift to step S03. When a human turns on the operation switch in step S03, the operation state is entered. In this state, the control device shifts to the state of step S05 and checks whether the water amount sensor is turned on. When a human opens the hot water tap in step S04, the water amount sensor is turned on in step S05, and the process proceeds to step S06. Since the water amount sensor is OFF until the human opens the hot water tap, the process waits in the state of step S05.
[0009]
In step S06, it is checked whether or not the sensors of the various safety devices are normal. When all the sensors indicate normal values, the combustion fan is turned on in step S07. In step S08, the value of the rotational speed sensor of the combustion fan is checked to determine whether the rotational speed is normal. If the engine speed is normal, the ignition device is turned on in step S09. Thereby, a spark is generated from the spark plug. Then, the process proceeds to step S10, and the original gas solenoid valve and the gas proportional valve are turned on (opened). Then, in step S11, the signal from the flame detector is checked, and when it becomes “flame detection”, the ignition device is turned off in step S12 because ignition is confirmed. Then, the process proceeds to step S13, and proportional control of the gas amount and the air amount is performed so that the desired hot water temperature is obtained and complete combustion is performed. This is a steady hot water supply state.
[0010]
In the steady hot water supply state, the malfunction of the safety device is monitored in step S14, and if it is not activated, the process proceeds to step S15 to check whether the water amount sensor is turned off. If the water amount sensor is not OFF, the process returns to step S13 and the control of the steady hot water supply state is continued.
[0011]
When a person closes the hot-water tap or water supply is stopped for other reasons, it is detected in step S15 that the water amount sensor has been turned off. The proportional valve is turned off (“closed”), the combustion fan is turned off in step S17, and the process returns to the initial state of step S04.
[0012]
When the safety device operates in the steady hot water supply state, the process jumps from step S14 to step S18 to display an error, and in step S19, the original gas solenoid valve and the gas proportional valve are turned off ("closed"), and in step S20. Turn off the combustion fan. In this state, a human sees an error display, and in step S21, the hot water tap is set to “closed”, and in step S22, the operation switch is set to “off”. Then, the error display S23 is turned off in step S23. In this state, the human turns off the power in step S24, and the cause is removed in step S25. When it is considered that the cause has been removed, the human returns to step S01 and turns on the power again.
[0013]
If an abnormality of each safety device sensor is found in step S06, the process proceeds to step S26 to display an error, and then proceeds to step S21.
If the rotational speed of the fan is abnormal in step S08, the process proceeds to step S27 to display an error, and then proceeds to step S20.
[0014]
In step S11, when the flame is not detected within a predetermined time, it is determined that the ignition has failed, and reignition is performed. That is, the ignition device is turned off in step S28, and the original gas solenoid valve and the gas proportional valve are turned off ("closed") in step S29. Then, it is determined whether or not the number of reignition attempts in step S30 is a predetermined number n or less. When it is n times or less, the process returns to step S08 and the ignition operation is performed again. When it exceeds n times, it is determined that the ignition system is defective, an error is displayed in step S27, and the process proceeds to step S21.
[0015]
The above flow chart shows a very schematic flow. Actually, there are many other control routines for ensuring safety, as well as control of the hot water supply amount and use of a bypass water amount adjustment valve. Many control routines are included, such as control of the hot water supply temperature and control of the capacity switching gas solenoid valve.
[0016]
In addition, the outputs of overheat prevention devices, afterfire safety devices, overpressure prevention safety devices, etc. are connected to safety devices composed of hardware in addition to the safety control using the above control devices. Even if the control device itself becomes defective, it does not lead to an accident such as a fire.
[0017]
The hot water heater shown in FIG. 3 is called a single can / one water channel type, and is the simplest one having one heat exchanger and one hot water channel in one water heater. Two cans with two heat exchangers and two hot water supply systems (for example, for hot water supply to a hot water tap and for reheating a bath), one can with one heat exchanger and two water supply systems There are various types such as a two-water channel type. The “hot water heater” in the present specification includes all these types of water heaters.
[0018]
However, in the water heater of the automatic control system as shown in FIG. 3, hot water having the same temperature is supplied to the kitchen and bath because there is only one hot water outlet. The temperature of the hot water can be set by remote control and can be changed according to the purpose as appropriate. For example, when the temperature of the hot water is set to 40 ° C. in a bath and a shower is taken, the temperature of the hot water is 40 in the kitchen. The problem that only hot water of ℃ is supplied.
[0019]
Moreover, the maximum temperature of the high temperature water heated with a heater is set to 60-75 degreeC for the purpose of the hot water supply to a bath. Therefore, when it is desired to use the hot water supplied from the water heater for cooking or beverage as it is, there is a problem that the temperature of the hot water is too low.
[0020]
[Problems to be solved by the invention]
In view of such circumstances, the present inventors have invented a water heater that can supply hot water that can be used for cooking and beverages in a state in which the same method of use as in the past has been made possible. A patent application was filed as No. 362134 (hereinafter referred to as “prior application invention”). An example of the embodiment of the invention of the prior application is shown in FIG. The configuration of the main part of the embodiment of the invention of the prior application shown in FIG. 5 is almost the same as that of the conventional water heater shown in FIG.
[0021]
A gas burner 12 and a heat exchanger 13 are provided in the water heater main body 11, and the water in the heat exchanger 13 is heated by the combustion heat of the gas burner 12. When the hot water tap is opened, water is supplied from the water supply system to the heat exchanger 13 through the water filter 14. Since the amount of water is detected by the water amount sensor 15, a control device (not shown) in the electrical board opens the original gas solenoid valve 16, applies a voltage to the spark plug 17, and gas is generated by the spark. Ignite. Thereby, the gas from the combustion pipe 18 is combusted, and the water in the heat exchanger 13 is heated.
[0022]
The water supply flow rate is controlled by the water amount adjustment valve 19, and the hot water supply temperature is detected by the hot water thermistor 20 to control the opening degree of the bypass water amount adjustment valve 21 and the opening degree of the gas proportional valve 22. To maintain the target temperature. For this control, the temperature of the feed water detected by the incoming water thermistor 23 and the temperature of the hot water at the outlet of the heat exchanger 13 detected by the can water thermistor 24 are simultaneously used. When the target hot water temperature is greatly different or the amount of water supply is greatly different and cannot be controlled by the opening degree of the bypass water amount adjusting valve 21 or the gas proportional valve 22, the gas burner is opened and closed by opening and closing the capacity switching gas electromagnetic valve 25. It responds by changing the combustion capacity of
[0023]
Combustion air is supplied from the combustion fan 26 to the gas burner 12. In order to detect whether or not combustion air is supplied, a rotation speed sensor 27 of the combustion fan 26 is provided. In addition to this, the rotation speed sensor 27 is used to control the rotation speed of the combustion fan 26 so as to supply an air volume corresponding to the gas volume.
[0024]
As a safety device, an overheat prevention sensor 28 for detecting overheating of the water heater main body, an overpressure prevention safety device 29 for preventing overheat in the heat exchanger 13 and the hot water supply pipe, and preventing it from draining, in the heat exchanger 13, an afterfire safety device 30 for detecting overheating of the heat exchanger 13 due to afterfire, a leakage safety device 31 for detecting leakage, a flame detector 32 for detecting gas combustion flame, and the like are provided.
[0025]
In the embodiment of the invention of the prior application, in addition to the above configuration, a high temperature hot water supply pipe 33 for supplying high temperature hot water heated by the heat exchanger 13 directly to the outside of the apparatus is provided, and the water purification device 34 is attached. It has been. Further, a check valve 35 is provided in the outlet side piping of the heat exchanger 13 after the branch point with the high temperature hot water supply pipe 33. When the hot water tap connected to the high temperature hot water supply pipe 33 is opened, the hot water heated by the heat exchanger 13 is supplied to the hot water tap through the water purification device 34. In this case, the control of the apparatus is the same as that shown in FIG.
[0026]
The check valve 35 prevents water that has passed through the bypass from flowing into the high-temperature hot water supply pipe 33 when performing high-temperature hot water supply and simultaneously performing appropriate-temperature hot water supply and high-temperature hot water supply. Of course, an electromagnetic valve may be used instead of the check valve 35, and the outflow from the high temperature hot water supply pipe 33 may be detected by a sensor to close the electromagnetic valve. However, the configuration is better when the check valve is used. It will be easy.
[0027]
However, the following problems remain in the water heater according to the invention of the prior application.
(1) Since hot water is always supplied when a hot water tap is opened, it is mistaken for a water tap that supplies hot water at an appropriate temperature (hereinafter referred to as an appropriate temperature hot water tap) If the hot water tap is opened, hot water may touch the human body and cause burns.
(2) Even if the hot water tap is opened, the hot water temperature may not rise immediately. In that case, it is necessary to check whether the human has reached the proper temperature, and there is a risk of burns. .
(3) If the heat exchanger sequence is started after opening the high-temperature hot-water tap, it may take some time to obtain hot water at an appropriate temperature.
(4) If high-temperature water flows into the sink or water pipe for a long time, the sink or water pipe may be damaged.
[0028]
The present invention has been made in view of such circumstances, and a hot water supply device that maintains safety even when the hot water tap is accidentally opened, and a hot water supply that does not need to be touched to check whether the hot water is at an appropriate temperature. It is an object of the present invention to provide an apparatus, a hot water supply apparatus that shortens the time required to reach an appropriate temperature, and a hot water supply apparatus in which high-temperature water does not flow for a long time.
[0029]
[Means for Solving the Problems]
The first means for solving the above-described problem is that the hot water heated by the heat exchanger is mixed with the water that has passed through the bypass water channel, and the normal hot water pipe that supplies hot water at an appropriate temperature is passed through the bypass water channel. It is a water heater having a high temperature hot water supply pipe that supplies high temperature hot water without mixing with water , and a solenoid valve is provided in the high temperature hot water supply pipe , and this solenoid valve is opened by a signal from the control device, And only when the hot-water tap connected to the high-temperature hot water supply pipe is opened, the hot water supply is performed from the high-temperature hot-water supply pipe, and when the hot water supply from the normal hot-water supply pipe is performed, A water heater having a function of closing a solenoid valve and stopping hot water supply from the high temperature hot water supply pipe .
[0030]
In this apparatus, an electromagnetic valve is provided in the high-temperature hot water supply pipe, and is closed in a normal state. Therefore, since hot water is not supplied from the faucet just by opening the hot water supply faucet, there is no burn even if it is opened by mistake. To perform hot water supply, first, the control device opens the solenoid valve by some human operation. When the high temperature hot water tap is opened in this state, high temperature hot water supply is performed. Thus, safety can be ensured by adding an operation for performing hot water supply in one step.
Further, when the capacity of the water heater is small, it does not have a capacity capable of simultaneously performing high temperature hot water supply and normal hot water supply. Therefore, when the normal hot-water hot-water tap is opened, the temperature of the high-temperature hot-water supply is lowered by an amount corresponding to the normal hot-water supply, and the proper temperature is not reached. Therefore, in this means, in order to prevent the use of hot water that is not at an appropriate temperature, when hot water is supplied from the regular hot water supply pipe, the solenoid valve is closed to stop the hot water supply from the high temperature hot water supply pipe. I have to.
[0041]
The second means for solving the above-mentioned problems is that the hot water heated by the heat exchanger is mixed with the water that has passed through the bypass water channel to mix the hot water with the normal temperature and the hot water supplied through the bypass water channel. It is a water heater having a high temperature hot water supply pipe that supplies high temperature hot water without mixing with water , and a solenoid valve is provided in the high temperature hot water supply pipe, and this solenoid valve is opened by a signal from the control device , And a hot water supply device that performs hot water supply from the high temperature hot water supply pipe only when the hot water tap connected to the high temperature hot water supply pipe is opened, and when the predetermined time has elapsed since the start of high temperature hot water supply, A water heater having a function of closing a valve.
[0042]
In this apparatus, an electromagnetic valve is provided in the high-temperature hot water supply pipe, and is closed in a normal state. Therefore, since hot water is not supplied from the faucet just by opening the hot water supply faucet, there is no burn even if it is opened by mistake. To perform hot water supply, first, the control device opens the solenoid valve by some human operation. When the high temperature hot water tap is opened in this state, high temperature hot water supply is performed. Thus, safety can be ensured by adding an operation for performing hot water supply in one step.
Further, in this means, when the predetermined time has elapsed since the start of the hot water supply, the solenoid valve is closed and the hot water supply is stopped, so that the hot water is kept in the sink and the water pipe for a long time. The flow, sink and water pipe are prevented from being damaged.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a water heater according to the first embodiment of the present invention. The basic configuration of FIG. 1 is the same as that of the embodiment of the prior invention shown in FIG. 5, and therefore, the same components are denoted by the same reference numerals, and the description of the operations of these common components is omitted. Only parts different from FIG. 5 will be described.
[0050]
The embodiment shown in FIG. 1 is different from the water heater shown in FIG. 5 in that a constant flow valve 36, an electromagnetic valve 37, and a normal hot water sensor 38 are provided in the high temperature hot water pipe 33. Among these, the constant flow valve 36 is for keeping the amount of hot water supplied from the high-temperature hot water tap constant and ensuring a sufficiently high temperature, and may be omitted in some cases. The electromagnetic valve 37 determines the performance which is the greatest feature of the present invention.
[0051]
When a human pushes a push button switch on an operation panel (not shown) for a predetermined time, the electrical board detects this and opens the electromagnetic valve 37, and performs pre-purge and standby in the water heater main body 11. That is, the sequence of S06 to S08 shown in FIG. 4 is advanced, the inside of the water heater main body 11 is pre-purged, and a state where ignition is OK at any time is created. The pre-purge and standby functions are for shortening the time from when the high-temperature hot water tap is opened until the appropriate temperature hot water is supplied. The reason why the solenoid valve 37 is not opened unless the push button switch is pressed for a predetermined time is to prevent the solenoid valve 37 from being opened when the push button switch is touched by mistake.
[0052]
In this state, when the high-temperature hot water tap is opened, sequence control similar to that of the prior invention is performed, and hot water is supplied from the high-temperature hot water tap. Even if the high temperature hot water tap is opened while the push button switch on the operation panel is not pressed for a predetermined time and the solenoid valve 37 is not opened, high temperature hot water is not supplied. Even if the tap and the normal hot water tap are opened by mistake, hot water is supplied and humans will not be burned.
[0053]
The temperature of the hot water supply is detected by the can water thermistor 24, and when the temperature of the hot water reaches an appropriate temperature (for example, 85 ° C.), the person is informed by a display or a sound device (not shown). You can use only hot water without touching it to check the temperature, preventing the possibility of burns, and instead of this method, you can simply put a thermo label on the hot water tap. In addition, the temperature may be displayed thereby.
[0054]
In this embodiment, a normal hot water supply sensor 38 is provided, and is turned on when normal hot water supply is being performed. In this state, the electrical board closes the solenoid valve 37 and stops the hot water supply. This is because if normal hot water supply and high temperature hot water supply are performed at the same time, it may not be possible to ensure the temperature of the can water sufficient to perform high temperature hot water supply, or the amount of high temperature hot water supply cannot be ensured. This is to prevent this from being performed.
[0055]
Further, the electrical board detects that the hot water supply is being performed when the water amount sensor 15 detects flowing water while the electromagnetic valve 37 is open. And when this state continues for a predetermined time, the solenoid valve 37 is turned off and the hot water supply is stopped. Normally, high-temperature hot water supply is used for beverages and cooking unlike hot water supply for baths and the like, so it is not used continuously for a long time. And by setting it as such a sequence, it can prevent that a high temperature water flows into a sink and a water distribution pipe over a long time, and a sink and a water distribution pipe are damaged.
[0056]
Further, when a push button switch (not shown) is pressed, the electrical board detects this, and the electromagnetic valve 37 is closed. As a result, the hot water supply cannot be used unless the push button is pressed again for a predetermined time. However, when a person forgets to press a push button that closes the solenoid valve 37, this function cannot be exhibited. Therefore, the electrical board is configured to turn off the electromagnetic valve 37 when a predetermined time has elapsed since the electromagnetic valve 37 was opened.
[0057]
FIG. 2 is a diagram showing an outline of a water heater according to the second embodiment of the present invention. The water heater branches from the high temperature hot water supply pipe 33 and is provided with a drain pipe 39, to which an electromagnetic valve 40 is attached, and the high temperature hot water supply is provided. The only difference from the embodiment shown in FIG. 1 is that the solenoid valve 41 is also attached to the pipe 33 after branching. Only the operation of this different point will be described below.
[0058]
Even when the hot water tap is opened and the gas burner 12 starts to burn, the temperature of the hot water supplied from the high temperature hot water tap does not immediately become an appropriate temperature for drinking or cooking. In this embodiment, when the solenoid valve 37 is opened, the solenoid valve 40 is simultaneously opened. Then, water flows into the water distribution pipe 39, the water amount sensor 15 detects the flowing water, and the gas burner 12 starts combustion.
[0059]
The temperature of the flowing hot water is detected by the can water thermistor 24. The electric circuit board opens the electromagnetic valve 40 and closes the electromagnetic valve 41 until this temperature reaches an appropriate temperature (for example, 85 ° C.). Therefore, until the hot water supply temperature reaches an appropriate temperature, the hot water is drained through the drain pipe 39 and is not supplied to the high temperature hot water tap. The electrical circuit board opens the electromagnetic valve 41 and closes the electromagnetic valve 40 in a state where the hot water temperature detected by the can water thermistor 24 has reached an appropriate temperature. Thereby, hot water of appropriate temperature comes to be supplied to the high temperature hot water tap. Needless to say, the solenoid valve 40 and the solenoid valve 41 may be changed to one distribution type three-way solenoid valve.
[0060]
【The invention's effect】
As described above, in the invention according to claim 1 of the present invention, safety can be ensured by adding an operation for performing hot water supply in one step.
In the invention which concerns on Claim 2, it can prevent that a solenoid valve opens in the case of an incorrect operation.
[0061]
In the invention which concerns on Claim 3, the time required for making the temperature of the hot water supplied from a high temperature hot-water tap into an appropriate temperature can be shortened only by the time required for pre-purge.
In the invention according to claim 4, it is not necessary for the human to touch the hot water to check the temperature, and the occurrence of burns or the like can be prevented.
[0062]
In the invention which concerns on Claim 5, it can prevent that the hot water which does not reach suitable temperature from a high temperature hot-water tap is supplied.
In the invention which concerns on Claim 6, the temperature of high temperature hot water supply falls, it does not become suitable temperature, and it can prevent that the hot water which is not suitable temperature is used.
[0063]
In the invention concerning Claim 7, it can prevent that a high temperature water flows into a sink or a water pipe over a long time, and a sink or a water pipe is damaged.
In the invention which concerns on Claim 8, even if a human forgets to turn off a solenoid valve, it can prevent that a solenoid valve remains on and it leads to a trouble occurrence.
[0064]
In the invention which concerns on Claim 9, clean hot water can be supplied for drinks or cooking.
In the invention which concerns on Claim 10, the hot water supplied can be directly used for drinking water or cooking.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a water heater according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an outline of a water heater according to a second embodiment of the present invention.
FIG. 3 is a diagram showing an outline of an example of a conventional water heater.
4 is a flowchart showing an outline of operation of the water heater shown in FIG. 3;
FIG. 5 is a diagram showing an outline of a water heater as an example of an embodiment of the invention of the prior application.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Hot water heater main-body part, 12 ... Gas burner, 13 ... Heat exchanger, 14 ... Water filter, 15 ... Water quantity sensor, 16 ... Original gas solenoid valve, 17 ... Spark plug, 18 ... Combustion pipe, 19 ... Water quantity control valve , 20 ... Hot water thermistor, 21 ... Bypass water amount control valve, 22 ... Gas proportional valve, 23 ... Inlet thermistor, 24 ... Can water thermistor, 25 ... Capability switching gas solenoid valve, 26 ... Combustion fan, 27 ... Number of revolutions Sensor: 28 ... Overheat prevention sensor, 29 ... Overpressure prevention safety device, 30 ... Afterfire safety device, 31 ... Leakage safety device, 32 ... Flame detector, 33 ... High temperature hot water supply pipe, 34 ... Water purification device, 35 ... Reverse Stop valve, 36 ... Constant flow valve, 37 ... Solenoid valve, 38 ... Normal hot water supply sensor, 39 ... Drain pipe, 40 ... Solenoid valve, 41 ... Solenoid valve

Claims (2)

A normal hot water supply pipe that supplies hot water at an appropriate temperature by mixing hot water heated by a heat exchanger with water that has passed through the bypass water channel, and high temperature hot water supply that supplies hot water without mixing with water that has passed through the bypass water channel a water heater and a pipe, and a solenoid valve is provided in the high-temperature hot water supply pipe, by a signal from the controller, the electromagnetic valve is opened, and the hot-water tap which is connected to the high-temperature hot water supply pipe opening between When the hot water supply is performed from the high temperature hot water supply pipe only when the normal hot water supply pipe is being used, the solenoid valve is closed and the hot water supply from the high temperature hot water supply pipe is provided. A hot water heater characterized by having a function of stopping. A normal hot water supply pipe that supplies hot water at an appropriate temperature by mixing hot water heated by a heat exchanger with water that has passed through the bypass water channel, and high temperature hot water supply that supplies hot water without mixing with water that has passed through the bypass water channel a water heater and a pipe, and a solenoid valve is provided in the high-temperature hot water supply pipe, by a signal from the controller, the electromagnetic valve is opened, and the hot-water tap which is connected to the high-temperature hot water supply pipe opening between A hot water supply apparatus that performs hot water supply from a high temperature hot water supply pipe only when it has become, and has a function of closing the solenoid valve when a predetermined time has elapsed since the start of high temperature hot water supply. Water heater.

Images