JP2019015417A - Hot water storage type water heater - Google Patents

Abstract

To inhibit the energy for heating water in the current time zone from being wasted in the next time zone.SOLUTION: A hot water storage type water heater for heating hot water in a tank includes a control part for setting a heating temperature to each of multiple time zones in a predetermined period. The control part heats the hot water so that temperature of the hot water in the tank becomes a value in accordance with heating temperature in the next time zone of the time zone, in an optional time zone in the predetermined period.SELECTED DRAWING: Figure 2

Description

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

  Patent Document 1 below discloses a hot water storage type water heater that performs a boiling operation for boiling water in a tank every time zone (for example, every hour). The boiling temperature of the boiling operation is set for each time zone, and is determined based on, for example, the amount of hot water used in the past in the past.

JP 2007-218519 A

  By the way, in the above-described boiling operation of the hot water storage type water heater, the temperature is controlled so that the hot water in the tank is always at the boiling temperature. Therefore, when the boiling temperature in the next time zone is lower than the boiling temperature in the current time zone, the energy that has been boiled in the current time zone may be wasted.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hot water storage type water heater that suppresses energy that has been boiled in the current time zone from being wasted in the next time zone. It is to be.

  One aspect of the present invention is a hot water storage type water heater that boils hot water in a tank, and includes a control unit that sets a boiling temperature in each of a plurality of time zones in a predetermined period, and the control unit includes the predetermined unit Hot water storage hot water characterized by boiling the hot water so that the temperature of the hot water in the tank becomes a value corresponding to the boiling temperature in the time zone next to the time zone in any time zone in the period It is a vessel.

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the controller is configured to raise a boiling temperature of the hot water in the tank in a time zone next to the time zone in an arbitrary time zone in the predetermined period. Boil the hot water so that

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the arbitrary time zone is a time zone in which the boiling temperature is higher than the boiling temperature in the next time zone among the plurality of time zones. It is.

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the control unit sets each boiling temperature in the plurality of time zones based on the amount of hot water used in the past.

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the control unit once boils the hot water in the tank at the boiling temperature in the time zone in the arbitrary time zone, and then The hot and cold water is boiled so as to maintain the boiling temperature in the next time zone.

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the control unit is capable of supplying hot water sterilized by heating at a timing at which use of the hot water in the tank by a user is assumed. Then, heating and disinfection of hot water in the tank is started.

  One aspect of the present invention is the above-described hot water storage type water heater, wherein the control unit notifies information related to the amount of hot water in the tank capable of supplying hot water.

  As described above, according to the present invention, it is possible to prevent the energy that has been boiled up in the current time zone from being wasted in the next time zone.

It is a figure which shows an example of schematic structure of the hot water storage type water heater A which concerns on one Embodiment of this invention. It is a figure explaining the setting method of the boiling temperature of the control part 17 which concerns on one Embodiment of this invention. It is a 1st figure explaining the effect in the setting method of the boiling temperature which concerns on one Embodiment of this invention. It is a 2nd figure explaining the effect in the setting method of the boiling temperature which concerns on one Embodiment of this invention. It is a 3rd figure explaining the effect in the setting method of the boiling temperature which concerns on one Embodiment of this invention.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention. In the drawings, the same or similar parts may be denoted by the same reference numerals and redundant description may be omitted. In addition, the shape and size of elements in the drawings may be exaggerated for a clearer description.

Hereinafter, a hot water heater according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of a schematic configuration of a hot water storage water heater A according to an embodiment of the present invention.

  The hot water storage type water heater A includes a water supply pipe 1, a first bypass pipe 2, a hot water supply pipe 3, a mixing valve 4, a second bypass pipe 5, a filter 6, a check valve 7, a first temperature detection unit 8, and a first electromagnetic valve. 9, the 2nd solenoid valve 10, the 2nd temperature detection part 11, the cutoff valve 12, the drain plug 13, the tank 14, the heater 15, the 3rd temperature detection part 16, and the control part 17 are provided.

  The water supply pipe 1 is connected to a tank 14. Thereby, the water which circulated through the water supply pipe 1 is supplied into the tank 14.

The first bypass pipe 2 is branched from the first branch portion 20 of the water supply pipe 1 and connected to the mixing valve 4. Specifically, one end of the first bypass pipe 2 communicates with the first branch portion 20 of the water supply pipe 1 and the other end communicates with the mixing valve 4.
One end of the hot water supply pipe 3 communicates with the upper part of the tank 14, and the other end communicates with the automatic water tap 100.

  The mixing valve 4 is provided in the middle of the hot water supply pipe 3. A first bypass pipe 2 branched from the water supply pipe 1 is communicated with the mixing valve 4. Thereby, in the mixing valve 4, the water supplied from the water supply pipe 1 and the hot water supplied from the hot water supply pipe 3 are mixed. In addition, an automatic temperature controller such as a thermostat (not shown) is provided inside the mixing valve 4. Therefore, the mixing ratio of hot water is controlled by the automatic temperature controller so that the hot water (mixed water) after mixing has a predetermined temperature (for example, 38 ° C. to 42 ° C.) suitable for use by the user or the like.

  The second bypass pipe 5 is branched from the second branch portion 21 of the water supply pipe 1 and connected to the hot water supply pipe 3 between the mixing valve 4 and the automatic water tap 100. Specifically, one end of the second bypass pipe 5 is connected to the second branch portion 21 of the water supply pipe 1, and the other end is connected to the hot water supply pipe 3 between the mixing valve 4 and the automatic water tap 100. The second branch portion 21 is provided on the upstream side of the first branch portion 20.

The filter 6 is provided on the upstream side of the second branch portion 21 in the water supply pipe 1. The filter 6 removes dust from the water flowing through the water supply pipe 1.
The check valve 7 is provided on the upstream side of the second branch portion 21 in the water supply pipe 1. The check valve 7 prevents the backflow of water flowing through the water supply pipe 1.

  The first temperature detector 8 is provided on the upstream side of the second branch portion 21 in the water supply pipe 1. The first temperature detection unit 8 detects the temperature of the water flowing through the water supply pipe 1 and transmits the detection result to the control unit 17.

  The first solenoid valve 9 is provided in the water supply pipe 1 between the first branch part 20 and the second branch part 21, and opens or closes the path of the water supply pipe 1. The opening degree of the first electromagnetic valve 9 is controlled by the control unit 17.

  The second electromagnetic valve 10 is provided in the second bypass pipe 5 and opens or closes the path of the second bypass pipe 5. The opening degree of the second electromagnetic valve 10 is controlled by the control unit 17.

  The second temperature detector 11 is provided on the downstream side of the mixing valve 4 in the hot water supply pipe 3. The second temperature detection unit 11 detects the temperature of the mixed water supplied from the mixing valve 4 to the automatic faucet 100 and transmits the detection result to the control unit 17.

  The shutoff valve 12 is provided in the hot water supply pipe 3 between the tank 14 and the mixing valve 4. The shutoff valve 12 prevents hot water in the tank 14 from flowing out of the tank 14 by natural convection.

  The drain plug 13 is provided on the downstream side of the water supply pipe 1. The drain plug 13 is opened to drain water when it is desired to drain water in the tank 14 during maintenance or the like.

  The tank 14 is configured as a hollow can body made of, for example, a metal material, and stores water flowing in from the water supply pipe 1.

  The heater 15 is provided in the tank 14. The heater 15 heats the water in the tank 14 to a predetermined temperature based on the control of the control unit 17.

  The third temperature detector 16 is provided in the tank 14 and detects the temperature of hot water in the tank 14. Then, the third temperature detection unit 16 transmits the detection result to the control unit 17. For example, the third temperature detection unit 16 is configured as, for example, a thermistor provided on the surface of the tank 14 in the vicinity of the heater 15.

  The control unit 17 controls each of the first electromagnetic valve 9 and the second electromagnetic valve 10 to be in an open state or a closed state. Specifically, when the hot water storage water heater A detects an object such as a hand when a detection sensor provided in the automatic faucet 100 detects a hot water heater A during a normal hot water operation, the detection result is transmitted to the control unit 17. . Therefore, the control part 17 controls the 1st solenoid valve 9 to a valve-opening state, when the said detection sensor detects objects, such as a hand, in normal hot-water driving | operation. As a result, the mixed water is supplied from the automatic faucet 100, and an amount of water corresponding to the supplied mixed water flows into the tank 14 through the water supply pipe 1.

  The control unit 17 always controls the second electromagnetic valve 10 to be in a closed state while the hot water storage type water heater A is in the hot water operation. On the other hand, the control unit 17 controls the second electromagnetic valve 10 to be in an open state when the hot water heater A is not in the hot water operation and when high temperature hot water is detected. Thereby, the control part 17 mixes water with the hot hot water which distribute | circulates the hot water supply pipe 3 at the time of a power failure, when the mixing valve 4 fails, etc., and the said hot hot water supplies water from the automatic water tap 100 To prevent it. The control unit 17 can detect that the hot water in the hot water supply pipe 3 is at a high temperature based on the detection signal from the second temperature detection unit 11 (the high temperature hot water detection).

  In addition, the controller 17 performs a so-called boiling operation in which the heater 15 is driven to raise the hot water stored in the tank 14 to the boiling temperature. This boiling operation is executed in each of a plurality of time zones in a predetermined period. For example, the control unit 17 divides a day into a plurality of time zones, and performs a boiling operation for each of the divided time zones. In addition, the boiling temperature of this boiling operation is set for every time slot | zone. Here, one of the features of the present invention is the method for setting the boiling temperature.

  Below, the setting method of the boiling temperature of the control part 17 which concerns on this embodiment is demonstrated using FIG. The controller 17 performs the first step and the second step when setting the boiling temperature at which the boiling operation is performed.

  The first step is a step of tentatively setting the boiling temperature for each time zone by the learning function. For example, the control unit 17 is equipped with a learning function, and by this learning function, the amount of hot water used in each time zone in the past is heated up in each time zone so that the temperature is as low as possible under the condition that the hot water does not run out. Temporarily set the temperature. In the following description, the temporary boiling temperature set in the first step is referred to as “temporary boiling temperature”. In other words, the temporary boiling temperature in each time zone is the temperature (desired temperature) of hot water to be supplied from the tank 14 in each time zone.

  The second step is a step of determining the boiling temperature of the heating operation in each time zone using the provisional boiling temperature in each time zone set in the first step. In the following description, the boiling temperature when the boiling operation is actually executed is referred to as “control boiling temperature”.

In the second step, the control unit 17 sets the control boiling temperature in an arbitrary time zone in a predetermined period to a value corresponding to the temporary boiling temperature in the time zone next to the arbitrary time zone. This arbitrary time zone may be each time zone of a plurality of time zones in a predetermined period, or may be a specific time zone of a plurality of time zones.
For example, the control unit 17 sets the control boiling temperature in an arbitrary time zone in a predetermined period to the same value as the temporary boiling temperature in the next time zone. In other words, in the second step, the control unit 17 changes the boiling temperature in an arbitrary time zone in the predetermined period set in the first step to the boiling temperature in the next time zone after that time zone. change.

  Thus, the control unit 17 sets the boiling temperature for each of a plurality of time zones in a predetermined period. And the control part 17 performs a boiling operation so that the hot water in the tank 14 may become the value according to the boiling temperature in the time slot | zone next to the said time slot | zone in the arbitrary time slots in a predetermined period. More specifically, in the first step, the control unit 17 sets a boiling temperature (temporary boiling temperature) for each of a plurality of time zones in a predetermined period. Then, the control unit 17 sets the value to an arbitrary time so that the hot water in the tank 14 becomes a value corresponding to the provisional boiling temperature in the next time zone in the arbitrary time zone in the predetermined period. Set the belt to the controlled boiling temperature and perform the boiling operation.

Below, the setting method of the control boiling temperature of a 2nd step is concretely demonstrated using FIG.
For example, as shown in FIG. 2, in a first step, the time zone temperatures _{T 1} increases _{P 1} in provisional boiling between times _{t 1} from time _{t 0,} the time zone P between time _{t 1} to time _{t 2} temperature T ₂ boiling provisional in _2, the time zone temperature T ₃ increased P ₃ in the provisional boiling between times t ₂ from time t ₃ to that set by the learning function. In this case, the control unit 17, a control boiling temperature of the time zone P _1, the temperature T ₂ boiling provisional next time period P _2, the next time zone control boiling temperature of the time zone P ₂ and provisional boiling temperature _{T 3} of the P _3.

In this way, the control unit 17 sets the control boiling temperature in the time zone P _n (where n is 1 or more) from time t _n−1 to time t _n to the provisional boiling temperature T in the next time zone P _{n + 1. Let n + 1} .
The controller 17 sets the boiling temperature (control boiling temperature) in an arbitrary time zone during the hot water operation (predetermined period) to the boiling temperature (temporary boiling temperature) in the next time zone after the arbitrary time zone. Set and perform boiling operation during the time period.

  Below, the effect in the setting method of the boiling temperature which concerns on one Embodiment of this invention is demonstrated using FIGS.

For example, in the first step, the temporary boiling temperature is 60 ° C. in the time zone from 14:00 to 15:00, and the temporary boiling temperature is 50 in the time zone from 15:00 to 16:00. Suppose that it is set to ° C.
In this case, since the conventional hot water storage type water heater does not have the second step, the heating operation is performed using the temporary boiling temperature set in the first step as the control boiling temperature. Become.

  Therefore, as shown in FIG. 3A, the conventional hot water heater is controlled so that the hot water in the tank 14 is always 60 ° C. during the time period from 14:00 to 15:00. . Here, in the next time zone, that is, the time zone from 15:00 to 16:00, the control boiling temperature is set to 50 ° C. lower than 60 ° C. Therefore, although the hot water in the tank 14 was always controlled at 60 ° C. until the time 15:00, the hot water in the tank 14 needs to be immediately reduced to 50 ° C. after the time 15:00, and the time 14: The energy boiled from 00 to 15:00 is wasted.

  On the other hand, in the second step, the hot water heater A according to the present embodiment sets the controlled boiling temperature in an arbitrary time zone to the boiling temperature in the time zone next to the time zone. Do the driving. For example, as shown in FIG. 3 (b), the hot water storage water heater A sets the control boiling temperature to 50 ° C. and executes the boiling operation in the time period from 14:00 to 15:00.

  Here, in the time zone from 14:00 to 15:00, the 60 ° C. hot water that has been boiled in the tank 14 by 14:00 is intermittently discharged, and the amount of new water that has been discharged When the water flows into the tank 14, a 60 ° C. hot water region and a water region coexist in the tank 14. And this area | region of water is controlled to 50 degreeC by the boiling operation of the time slot | zone from time 14:00 to time 15:00. Therefore, as shown in FIG. 4A, a boundary layer between the 60 ° C. hot water region and the 50 ° C. hot water region is generated in the tank 14. Accordingly, when the hot water in the tank 14 is intermittently discharged in the time period from 14:00 to 15:00, the boundary layer rises. At time 15:00, the boundary layer disappears, and as shown in FIG. 4B, the hot water of 50 ° C. is stored in the tank 14 as a whole. As a result, the hot water heater A does not need to immediately lower the hot water in the tank 14 to 50 ° C. after the time 15:00, and the energy raised from the time 14:00 to the time 15:00 is wasted. Never become.

  The effect by this said embodiment becomes more remarkable in the last time slot | zone out of the time slot | zone which performs a hot water supply driving | operation. For example, as shown in FIG. 5, it is assumed that the time zone from time 22:00 to time 23:00 is the last time zone in which the hot water operation is performed, and the provisional boiling temperature is set to 60 ° C. In the time zone after time 23:00, the boiling temperature (freezing prevention temperature) is set at a temperature sufficiently lower than 60 ° C. to prevent freezing.

Even in this case, the conventional hot water storage type water heater always controls the hot water in the tank 14 to 60 ° C. in the time zone from 22:00 to 23:00, so that the time in the tank 14 after the time 23:00 It is necessary to dissipate the hot water, and energy is wasted (FIG. 5 (a)).
On the other hand, the hot-water storage water heater A according to the present embodiment performs the boiling operation by setting the control boiling temperature to the anti-freezing temperature in the time zone from 22:00 to 23:00. Thus, at time 23:00, the hot water in the tank 14 is almost controlled to the freezing prevention temperature (FIG. 5B). Therefore, after time 23:00, it is not necessary to dissipate the hot water in the tank 14, and waste of energy can be suppressed.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

(Modification 1) In the above-described embodiment, the control unit 17 sets the boiling temperature (control boiling temperature) in an arbitrary time zone during the tapping operation to the boiling temperature (temporary) in the next time zone. Although the boiling operation was executed as the boiling temperature), the present invention is not limited to this. For example, the control unit 17 may set the control boiling temperature in any time zone to any temperature between the temporary boiling temperature in the time zone and the temporary boiling temperature in the next time zone. . For example, when the temporary boiling temperature in the time zone P ₁ is 60 ° C. and the temporary boiling temperature in the time zone P ₂ is 50 ° C., the control unit 17 sets the control boiling temperature in the time zone P ₁ to 60 ° C. You may set to the temperature between 50 degreeC and 50 degreeC. Thereby, the control part 17 can suppress waste of energy rather than the past.

(Modification 2) In the above embodiment, each time zone when the predetermined period is divided into a plurality of time zones is set as an arbitrary time zone, but the present invention is not limited to this. For example, the control unit 17 sets a time zone in which the temporary boiling temperature is higher than the temporary heating temperature in the next time zone as an arbitrary time zone among the time zones when the predetermined period is divided into a plurality of time zones. Also good. For example, when the temporary boiling temperature in the time zone P ₁ is 60 ° C. and the temporary boiling temperature in the time zone P ₂ is 50 ° C., the control unit 17 sets the control boiling temperature in the time zone P ₁ to 50 ° C. Set the temperature to between. When the temporary boiling temperature in the time zone P ₁ is 60 ° C. and the temporary boiling temperature in the time zone P ₂ is 70 ° C., the control unit 17 sets the control boiling temperature in the time zone P ₁ to the time Set to the temporary boiling temperature (60 ° C.) of band P ₁ . That is, in the second step, the control unit 17 sets the control boiling temperature in the time zone not corresponding to the arbitrary time zone to the temporary boiling temperature in the time zone set in the first step.

(Modification 3) In the above embodiment, the boiling temperature for each time period is set by the learning function in the first step, but the present invention is not limited to this. For example, in the first step, the boiling temperature for each time period may be set by an input operation by a user operation unit. This operation unit may be provided in the hot water storage type water heater A, or may be a portable terminal, a remote control, or the like.

(Modification 4) In the above-described embodiment, the control unit 17 always performs the boiling operation at the temporary boiling temperature in the previous time zone during an arbitrary time zone. It is not limited. For example, the control unit 17 temporarily boils hot water in the tank 14 at a temporary boiling temperature in an arbitrary time zone and maintains the temporary boiling temperature in a time zone next to the time zone in an arbitrary time zone. The boiling operation may be executed. That is, the control unit 17 once raises the temporary boiling temperature in the time zone as the control boiling temperature in the arbitrary time zone, and then changes the temporary boiling temperature in the next time zone to the control boiling temperature. May be boiled up.

(Modification 5) In the above embodiment, the hot water heater A may be sterilized by heating the hot water in the tank 14 at a high temperature with the heater 15 in a preset time zone. Thereby, when the hot water in the tank 14 is not used for a long time, the hot water storage water heater A can sterilize the hot water in the tank 14 and keep the inside of the tank 14 hygienic. Note that the preset time zone is preferably a time zone in which the user uses the hot water in the tank 14 at a low frequency, for example, a morning time zone.
More specifically, for example, the control unit 17 may start heat disinfection in advance so that hot water disinfected by heat can be supplied at a timing assumed to be used by the user. The timing assumed to be used by the user may be set in advance by a learning function in the control unit 17. In addition, the timing which starts heat disinfection is the time slot | zone when it is estimated that the hot water in the tank 14 is not used by the user, for example. This time zone may be set in advance by a learning function in the control unit 17. However, this time zone is a time zone in which it is estimated that the hot water in the tank 14 is not used by the user, and does not have to be a time zone in which the user is not actually used.

Further, in the fifth modification, the control unit 17 may start the heat disinfection in response to the specific condition being satisfied before starting the heat disinfection in advance. The specific condition is, for example, that the time zone in which the hot water in the tank 14 is estimated not to be used is a long time.
For example, the control unit 17 can supply hot water that has been disinfected by heating at a timing that is assumed to be used by the user only when the time zone in which the hot water in the tank 14 is estimated not to be used is long. Heat disinfection may be started in advance. When the time zone in which the hot water in the tank 14 is estimated not to be used is a long time, it means that the hot water in the tank 14 is used in the time zone in which the hot water in the tank 14 is estimated to be unused. This is a case where it is estimated that an undesirable time elapses. Specifically, when the time zone in which the hot water in the tank 14 is estimated not to be used exceeds a predetermined time, the control unit 17 determines that the time zone is not used for a long time.
Here, it is desirable that the timing for starting the heat disinfection is immediately before the timing at which the use by the user is assumed. Furthermore, it is desirable that the timing at which the heat disinfection is completed is immediately before the timing at which use by the user is assumed or immediately after the timing at which use by the user is assumed. Therefore, the timing for starting the heat sterilization is set so that the difference between the timing when the heat sterilization ends and the timing assumed to be used by the user is within a predetermined range.
The controller 17 heats the hot water in the tank 14 with the heater 15 at a high temperature when the hot water in the tank 14 is used again after a time zone in which the hot water in the tank 14 is not used for a long time. It may be disinfected by heating.

(Modification 6)
In the above embodiment, the hot water heater A may notify how many more hot water in the tank 14 (hot water discharged from the automatic faucet 100) can be used. This notification may be voice, display, or a combination of voice and display. This display is, for example, a display by a display device (not shown) mounted on the hot water storage water heater A. For example, the control unit 17 informs how many more people are using in the last time zone (time zone from 22:00 to 23:00 in FIG. 5) in which the hot water operation is performed. Here, the use is, for example, hand washing.
However, the content to be notified is not limited to the number of users who can use the hot water in the tank 14. That is, the information to be notified may be information obtained by digitizing or iconifying information on the amount of hot water in the tank 14 that can be used by the user.

(Modification 7) In the above embodiment, the case where the hot water storage type water heater A is the original stop type has been described, but the present invention is not limited to this. For example, the hot water storage type water heater A may be a first stop type.

  As described above, the hot water storage type water heater A includes the control unit 17 that sets the boiling temperature in each of a plurality of time zones in a predetermined period. And this control part 17 performs a boiling operation so that the hot water in the tank 14 may become the value according to the boiling temperature in the time slot | zone next to the said time slot | zone in the arbitrary time slots in the predetermined period. Thereby, the hot water storage type water heater A can suppress that the amount of energy heated up in the current time zone is wasted in the next time zone.

  Further, the control unit 17 of the hot water storage type water heater A performs a boiling operation so that the hot water in the tank 14 becomes a boiling temperature in a time zone next to the time zone in an arbitrary time zone in the predetermined period. To do. Thereby, the hot water storage type water heater A can further suppress that the amount of energy heated up in the current time zone is wasted in the next time zone.

  Moreover, the hot water storage type water heater A sets an arbitrary time zone as a time zone in which a boiling temperature is higher than a boiling temperature in a next time zone among a plurality of time zones of a predetermined period. Thereby, when the boiling temperature in the next time zone is higher than the current time zone, the hot water storage water heater A sets the boiling temperature in the current time zone to the boiling temperature set in the first step. As a result, the waste of energy can be suppressed.

A Hot water storage type water heater 1 Water supply pipe 2 First bypass pipe 3 Hot water supply pipe 4 Mixing valve 5 Second bypass pipe 6 Filter 7 Check valve 8 First temperature detector 9 First solenoid valve 10 Second solenoid valve 11 Second temperature Detector 12 Shut-off valve 13 Drain plug 14 Tank 15 Heater 16 Third temperature detector 17 Controller

Claims (7)

A hot water heater that boils hot water in the tank,
A control unit that sets the boiling temperature in each of a plurality of time zones in a predetermined period,
The controller is configured to boil the hot water so that the temperature of the hot water in the tank becomes a value corresponding to the boiling temperature in a time zone next to the time zone in an arbitrary time zone in the predetermined period. A hot water storage type water heater that is characterized.   2. The hot water storage system according to claim 1, wherein the controller is configured to boil the hot water so that the hot water in the tank has a boiling temperature in a time zone next to the time zone in an arbitrary time zone in the predetermined period. Water heater.   The hot water storage water heater according to claim 1, wherein the arbitrary time zone is a time zone in which the boiling temperature is higher than the boiling temperature in the next time zone among the plurality of time zones.   The hot water storage water heater according to any one of claims 1 to 3, wherein the control unit sets each boiling temperature in the plurality of time zones based on an amount of hot water used in the past.   The controller is configured to keep the hot water in the tank so that the hot water in the tank is once heated at the boiling temperature in the time zone and then kept at the boiling temperature in the time zone next to the time zone. The hot water storage water heater according to any one of claims 1 to 4, which is heated up.   The said control part starts the heat disinfection of the hot water in the said tank beforehand so that the hot water which was heat-sterilized can be supplied at the timing when the use of the hot water in the said tank by the user is assumed. The hot water storage water heater according to any one of 5.   The hot water storage water heater according to any one of claims 1 to 6, wherein the control unit notifies information related to an amount of hot water in the tank that is capable of supplying hot water.

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