JP2012180968A - Water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater which allows failure with a temperature-sensing means to be detected even when a plurality of temperature-sensing means are not installed in series on a hot-water supply path downstream of a mixing valve and which allows failure with the temperature-sensing means to be detected without a decrease in user's convenience and allows a broken temperature-sensing means to be easily identified.SOLUTION: The water heater is equipped with a water temperature sensor 20 to sense a temperature of water to be supplied to the mixing valve 14, a residual-hot-water temperature sensor 18 to sense a temperature of hot water to be supplied to the mixing valve 14, and a hot-water sensor 21 to sense a temperature of hot water leaving the mixing valve 14. An agreement/disagreement of a temperature sensed by the hot-water sensor 21 with a calculated hot-water temperature or a target temperature is determined by a first failure determination treatment. When a disagreement is determined by the first failure determination treatment, second failure determination treatment is performed to determine an agreement/disagreement of a temperature sensed by the water temperature sensor 20 with a temperature sensed by the hot-water sensor 21 after the mixing valve 14 is controlled to be in the full open state for the water side.

Description

  The present invention relates to a water heater.

  Conventionally, in a water heater, hot water supplied from a hot water source such as a hot water storage tank and water supplied from a water source are mixed by a mixing valve, and the temperature of the mixed hot water is detected by a temperature sensor, and the detection is performed. By controlling the mixing ratio of the mixing valve so that the set temperature becomes the temperature set by the user, hot water supply at the temperature desired by the user is realized. In such a water heater, if the temperature sensor fails, there is a possibility that it will lead to high temperature hot water. For this reason, when a temperature sensor breaks down, it is desired to detect it quickly and reliably. In the case of a fault that causes extreme output fluctuations such as disconnection or short circuit among the faults of the temperature sensor, it is easy to detect the fault. On the other hand, in the case of a failure that does not cause extreme output fluctuations, such as when the sensor performance gradually decreases and the detection error gradually increases, it is not easy to detect the failure.

  As an invention in view of the above points, Patent Document 1 is provided in series with a water supply temperature sensor that detects the temperature of water supplied from a cold water supply source, and a hot water supply path downstream of the mixing valve, Compare the temperatures detected by the feed water temperature sensor and the temperature sensor group with at least two temperature sensor groups that detect the temperature of the water supplied to the hot water use location and the opening of the mixing valve fully open on the water side. A temperature comparison means, and in the temperature comparison means, when a temperature difference of a predetermined temperature or more is detected between one temperature sensor and any other temperature sensor, the temperature sensor in which the temperature difference is detected A hot water supply system that determines a failure and stops hot water supply is disclosed.

JP 2009-216352 A

  However, the conventional technique disclosed in the above publication has a problem that a failure cannot be detected unless there are two or more temperature sensor groups in series on the hot water supply path downstream of the mixing valve. . Further, in the conventional technique disclosed in the above publication, when performing the temperature sensor failure detection process, it is first necessary to open the opening of the mixing valve to the water side fully open. For this reason, even if there is no abnormality in any temperature sensor, cold water will flow out of the mixing valve for a certain period of time against the user every time failure detection processing is performed. Inconvenient.

  The present invention has been made to solve the above-described problems, and detects a failure of the temperature detection means even when there are no plurality of temperature detection means in series on the hot water supply path downstream of the mixing valve. An object of the present invention is to provide a water heater that can detect a failure of the temperature detecting means without damaging the user's usability as much as possible and that can easily identify the failed temperature detecting means. And

  The water heater according to the present invention mixes water supplied from a water source and hot water supplied from a hot water source and can change the mixing ratio thereof, and the temperature of water supplied from the water source. Water source temperature detecting means for detecting water temperature, hot water source temperature detecting means for detecting the temperature of hot water supplied from the hot water source, hot water supply temperature detecting means for detecting the temperature of hot water flowing out of the mixing valve, and flowing out of the mixing valve Mixing valve control means for controlling the mixing ratio of the mixing valve so that the temperature of the hot water becomes the target temperature, the temperature detected by the water source temperature detecting means, the temperature detected by the hot water source temperature detecting means, the mixing valve Based on the mixing ratio information, the calculated hot water temperature calculating means for calculating the calculated temperature of the hot water flowing out from the mixing valve, the temperature detected by the hot water temperature detecting means, and the calculated hot water temperature calculating means Temperature or eye The first failure determination means for performing a first failure determination process for determining whether the temperature matches or does not match, and when the first failure determination process determines that there is a mismatch, the mixing valve is controlled to be in a fully open state on the water side And a second failure determination means for performing a second failure determination process for determining a match / mismatch between the temperature detected by the water source temperature detection means and the temperature detected by the hot water supply temperature detection means. Is.

  According to the present invention, it is possible to detect a failure of the temperature detecting means even when there are no plurality of temperature detecting means in series on the hot water supply path downstream of the mixing valve. Further, it is possible to detect a failure of the temperature detecting means without impairing the convenience of the user as much as possible. In addition, it becomes easy to specify the failed temperature detecting means.

It is a block diagram which shows the water heater of Embodiment 1 of this invention. It is a flowchart of the hot_water | molten_metal supply control performed by the control apparatus in Embodiment 1 of this invention. It is a flowchart of the failure determination process for the maintenance inspection performed by the control apparatus in Embodiment 1 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram illustrating a water heater according to Embodiment 1 of the present invention. As shown in FIG. 1, the water heater of the present embodiment includes a tank unit 1 having a hot water storage tank 2 built therein, and a heat pump unit 3 that heats water to generate hot water. The heat pump unit 3 can generate hot water with high efficiency by absorbing the heat of the atmosphere. The tank unit 1 and the heat pump unit 3 are connected by heat pump circulation pipes 7 and 8. Water supplied from a water source such as water supply flows into the pressure reducing valve 12 through the water supply pipe 4, is decompressed to a predetermined pressure, and then flows into the lower part of the hot water storage tank 2 through the water supply pipe 5. In the hot water storage tank 2, the water source water pressure reduced to a predetermined pressure by the pressure reducing valve 12 acts from the water supply pipes 4 and 5. The hot water storage tank 2 is always kept full. The water decompressed by the pressure reducing valve 12 is also supplied to the mixing valves 14 and 15 through the water supply pipe 6.

  During the boiling operation of the hot water storage tank 2, the water in the hot water storage tank 2 is taken out from the lower part of the hot water storage tank 2, and is sent to the heat pump unit 3 through the heat pump circulation pipe 7 by the operation of the heat pump circulation pump 23, heated and heated. It becomes. This hot water returns to the tank unit 1 through the heat pump circulation pipe 8 and flows into the hot water storage tank 2 from the upper part of the hot water storage tank 2 through the bypass valve 13. By performing such boiling operation, hot water is stored in the hot water storage tank 2 from the upper part to the lower part. The upper hot water and the lower water in the hot water storage tank 2 are maintained without being mixed with each other through the temperature boundary layer because of the difference in specific gravity.

  When supplying hot water, the hot water taken out from the upper part of the hot water storage tank 2 is sent to the mixing valves 14 and 15 through the hot water source pipe 9. The mixing valves 14 and 15 mix hot water sent from the hot water source pipe 9 and water sent from the water supply pipe 6 to discharge hot water whose temperature is adjusted. Hot water discharged from the mixing valve 14 is supplied to a predetermined hot water supply destination such as a faucet (not shown) through the hot water supply pipe 10. Hot water discharged from the mixing valve 15 is supplied to a bathtub (not shown) through the bath pipe 11.

  The mixing valves 14 and 15 can change the mixing ratio of water and hot water. The mixing valves 14 and 15 of the present embodiment can arbitrarily change the mixing ratio between the water side fully open state that maximizes the water mixing ratio and the hot water side fully open that maximizes the mixing ratio of hot water. it can. In the present embodiment, it is assumed that the mixing ratio is water 100: hot water 0 when the water side is fully open, and the mixing ratio is water 0: hot water 100 when the water side is fully open. The mixing valves 14 and 15 are configured to change the mixing ratio by the operation of the stepping motor.

  A check valve 16 for preventing a backflow is installed in each of the water supply pipe 4, the water supply pipe 6, the hot water source pipe 9, the hot water supply pipe 10, and the bath pipe 11. The water supply pipe 4 is further provided with a water supply temperature sensor 20 (water source temperature detection means) for detecting the temperature of water supplied from the water source. A hot water temperature sensor 18 (hot water source temperature detecting means) for detecting the temperature of hot water at the uppermost part of the hot water storage tank 2 is provided at the uppermost part of the hot water storage tank 2. The remaining hot water temperature sensor 18 can detect the temperature of hot water supplied from the hot water source pipe 9. The hot water storage tank 2 is further provided with a plurality of remaining hot water temperature sensors 19 at different heights. The hot water source pipe 9 is further provided with a relief valve 17. The hot water supply pipe 10 is further provided with a hot water supply temperature sensor 21 (hot water supply temperature detecting means) for detecting the temperature of the hot water flowing out of the mixing valve 14 and supplied to the hot water supply destination. The bath pipe 11 is further provided with a bath hot water temperature sensor 22 (hot water temperature detecting means) for detecting the temperature of hot water flowing out of the mixing valve 15 and supplied to the bathtub.

  A control device 24 is provided inside the tank unit 1. Actuators and sensors included in the hot water supply device are electrically connected to the control device 24. The control device 24 is connected via a communication line 25 to a remote control 26 as a user interface installed in, for example, a kitchen or bathroom. The control device 24 controls the entire hot water supply device. For example, the control device 24 manages the amount of stored hot water by measuring the internal temperature of the hot water storage tank 2 using the remaining hot water temperature sensors 18 and 19. The control device 24 can detect the mixing ratio of the mixing valves 14 and 15 based on the number of steps of the stepping motor provided in the mixing valves 14 and 15.

  FIG. 2 is a flowchart of hot water supply control executed by control device 24 in Embodiment 1 of the present invention. Here, the case where hot water is supplied from the hot water supply pipe 10 side will be described as a representative, but the same applies to the case where hot water is supplied from the bath pipe 11 side.

  In step S11 of FIG. 2, when hot water supply is started by opening a hot water tap (not shown) at the end of the hot water supply pipe 10, the hot water in the upper part of the hot water storage tank 2 passes through the hot water source pipe 9 and the mixing valve 14 and water from the water source is supplied to the mixing valve 14 through the water supply pipes 4 and 6. When the hot water supply is started, the control device 24 adjusts the mixing ratio of the mixing valve 14 so that the temperature of the hot water flowing out from the mixing valve 14 and supplied to the hot water supply pipe 10 becomes the set temperature (target temperature) ( Step S12). This target temperature is a temperature set in advance by temperature setting means such as the remote controller 26. Control device 24 determines whether or not the detected temperature of hot water supply temperature sensor 21 matches the set temperature while performing the process of step S12 (step S13). In this step S13, when the difference between the set temperature and the detected temperature of the hot water supply temperature sensor 21 exceeds a certain value, it is determined that the two do not match, and the process of step S12 is continued. On the other hand, if the difference between the set temperature and the detected temperature of the hot water supply temperature sensor 21 is within a certain value in step S13, it is determined that the two match, and the process proceeds to step S14.

  In step S14, a first failure determination process is performed to determine whether the detected temperature of hot water supply temperature sensor 21 matches the calculated hot water supply temperature. The calculated hot water temperature is a calculated hot water temperature calculated by the control device 24 based on the detected temperature of the hot water temperature sensor 20, the detected temperature of the remaining hot water temperature sensor 18, and the mixing ratio information of the mixing valve 14. is there. For example, when the mixing ratio of the mixing valve 14 is water 50: hot water 50, the detected temperature of the remaining hot water temperature sensor 18 is 90 ° C., and the detected temperature of the feed water temperature sensor 20 is 10 ° C., the calculated hot water supply temperature Is calculated as (90 + 10) / 2 = 50 ° C. If the remaining hot water temperature sensor 18, the hot water temperature sensor 20, and the hot water temperature sensor 21 are all normal, the temperature detected by the hot water temperature sensor 21 and the calculated hot water temperature should match. In step S14, the controller 24 determines that the absolute value of the difference between the temperature detected by the hot water supply temperature sensor 21 and the calculated hot water supply temperature exceeds a predetermined allowable temperature difference (for example, 10 ° C.) for a predetermined allowable time (for example, 5 seconds). If the temperature continues for more than, it is determined that the detected temperature of the hot water supply temperature sensor 21 and the calculated hot water supply temperature do not match. On the other hand, when the absolute value of the difference between the detected temperature of the hot water temperature sensor 21 and the calculated hot water temperature does not exceed the allowable temperature difference, it is not recognized that the state exceeds the allowable time. It is determined that the detected temperature of the sensor 21 matches the calculated hot water supply temperature. When it is determined that the detected temperature of the hot water supply temperature sensor 21 matches the calculated hot water supply temperature, the process proceeds to step S15 and the hot water supply to the hot water supply pipe 10 is continued.

  On the other hand, when it is determined in the first failure determination process of step S14 that the detected temperature of the hot water supply temperature sensor 21 and the calculated hot water supply temperature do not match, the remaining hot water temperature sensor 18, the hot water temperature sensor 20, the hot water supply temperature. One of the sensors 21 may be out of order. In this case, the second failure determination process (steps S16 and S17) is executed to determine the temperature sensor that has failed. In step S16, the mixing valve 14 is controlled to a fully open state on the water side. At this time, for example, it is desirable to gradually change the mixing ratio of the mixing valve 14 over a period of about 5 seconds so that the water side is fully opened. As a result, sudden changes in the hot water supply temperature can be mitigated, so even if the hot water in the hot water supply pipe 10 is used for a shower or the like, the user can be surprised.

  After the mixing valve 14 is in the fully open state on the water side in step S16, the process proceeds to step S17, and processing for determining whether the detected temperature of the feed water temperature sensor 20 matches the detected temperature of the hot water temperature sensor 21 is performed. . In the state where the mixing valve 14 is fully opened on the water side, only water supplied from the water supply pipes 4 and 6 flows into the hot water supply pipe 10, so if both the water supply temperature sensor 20 and the hot water supply temperature sensor 21 are normal, the detected temperatures of both are detected. Should match. In step S17, the controller 24 determines that the absolute value of the difference between the detected temperature of the feed water temperature sensor 20 and the detected temperature of the hot water temperature sensor 21 exceeds a predetermined allowable temperature difference (for example, 10 ° C.) for a predetermined allowable time ( For example, if it continues for more than 5 seconds, it is determined that the detected temperature of the feed water temperature sensor 20 and the detected temperature of the hot water supply temperature sensor 21 do not match. In this case, the process proceeds to step S20, the hot water supply to the hot water supply pipe 10 is stopped, and the failure is notified by a method such as displaying an error on the remote controller 26 or the like. In addition, as a method of stopping the hot water supply to the hot water supply pipe 10, it can be stopped by a method such as closing an electromagnetic valve (not shown) provided in the hot water supply pipe 10, for example.

  If it is determined in step S17 that the detected temperature of the feed water temperature sensor 20 and the detected temperature of the hot water supply temperature sensor 21 do not coincide with each other, either the feed water temperature sensor 20 or the hot water supply temperature sensor 21 has a failure or a failure is possible. It can be determined that there is sex. If the hot water supply temperature sensor 21 is malfunctioning, the hot water supply temperature from the hot water supply pipe 10 cannot be accurately detected. Therefore, when hot water is supplied, hot water having a temperature higher than the set temperature continues. May be supplied to the user (hereinafter referred to as “high temperature hot water”). On the other hand, in this embodiment, when it is determined in step S17 that the detected temperature of the hot water temperature sensor 20 and the detected temperature of the hot water temperature sensor 21 are inconsistent, the case where the hot water temperature sensor 21 is out of order is considered. In step S20, the hot water supply is stopped. For this reason, high temperature hot water can be reliably prevented, and high safety can be obtained. In step S20, the fact that the failure point is either the water supply temperature sensor 20 or the hot water supply temperature sensor 21 may be notified.

  On the other hand, in step S17, it is not recognized that the state where the absolute value of the difference between the detected temperature of the feed water temperature sensor 20 and the detected temperature of the hot water temperature sensor 21 exceeds the allowable temperature difference continues beyond the allowable time. In this case, it is determined that the detected temperature of the feed water temperature sensor 20 and the detected temperature of the hot water supply temperature sensor 21 match. In this case, it is possible to determine that both the water supply temperature sensor 20 and the hot water supply temperature sensor 21 are not malfunctioning. Therefore, in this case, it can be determined that the remaining hot water temperature sensor 18 has a failure or a possibility of failure. In this case, next, the process proceeds to step S18 to execute a third failure determination process. In the third failure determination process of step S18, the number of times that the determination operation (second failure determination process) leading to step S17 is executed within a predetermined period (for example, within the past week) is a predetermined number of times (for example, 6 times). ). According to the process of step S18, it can be determined whether or not the remaining hot water temperature sensor 18 has a definite failure. In step S18, if the number of executions of the second failure determination process within the past predetermined period is less than the predetermined number, that is, if the failure of the remaining hot water temperature sensor 18 is not definitive, the process proceeds to step S15, and hot water supply The hot water supply to the pipe 10 is continued. On the other hand, when the number of executions of the second failure determination process in the past predetermined period has reached the predetermined number, that is, when the remaining hot water temperature sensor 18 has a definite failure, hot water supply to the hot water supply pipe 10 is continued. At the same time, the user is notified of the failure by displaying an error on the remote control 26 or the like. At this time, the fact that the failure location is the remaining hot water temperature sensor 18 may also be notified.

  As described above, in the present embodiment, when it is determined that they match in the second failure determination process, that is, the failure location is the remaining hot water temperature sensor 18, and the hot water supply temperature sensor 21 (and the supply water temperature sensor 20) has a failure. If it can be determined that there is no hot water, the hot water supply to the hot water supply pipe 10 is continued. When the hot water supply temperature sensor 21 is normal, the hot water supply temperature from the hot water supply pipe 10 can be accurately detected. Therefore, the controller 24 feeds back the detected temperature of the hot water supply temperature sensor 21 and the control device 24 mixes the mixing ratio of the mixing valve 14. By adjusting the temperature, it is possible to control the hot water supply temperature from the hot water supply pipe 10 to the set temperature. For this reason, since it is thought that there is no possibility that high temperature hot water will generate | occur | produce, it can be said that it is not necessary to stop hot water supply on the surface of safety. Therefore, in this case, the process proceeds to step S15 or S19 to continue hot water supply.

  As described above, according to the control of the present embodiment, the mixing valve 14 is not forcibly controlled to be fully opened on the water side in the first failure determination process. That is, the mixing valve 14 is not forcibly controlled to be fully opened on the water side unless any of the remaining hot water temperature sensor 18, the hot water temperature sensor 20, and the hot water temperature sensor 21 fails. For this reason, it can suppress that cold water is supplied to the hot water supply piping 10 contrary to a user's will, and can improve a user's usability.

  On the other hand, unlike the present invention, in the system that performs the failure detection process by forcibly controlling the mixing valve to be fully opened on the water side periodically, even when the temperature sensor has not failed, Every time the failure detection process is performed, the cold water is supplied to the hot water supply pipe against the user's will, so that the usability is deteriorated.

  Further, according to the control of the present embodiment, it is determined that there is a mismatch in the first failure determination process, and any of the remaining hot water temperature sensor 18, the hot water temperature sensor 20, and the hot water temperature sensor 21 may be out of order. In this case, it is possible to determine whether the remaining hot water temperature sensor 18 is defective or the water supply temperature sensor 20 or the hot water temperature sensor 21 is defective by performing the second failure determination process. As a result, it becomes easy to identify a faulty part during repair, and repair can be performed smoothly and quickly. Further, when there is a possibility of hot hot water supply (when there is a possibility of failure of the hot water supply temperature sensor 21) and when there is no possibility of high temperature hot water supply (the hot water supply temperature sensor 21 is normal, the remaining hot water temperature sensor 18 Therefore, the hot water supply can be stopped only when there is a possibility of high temperature hot water supply, and the hot water supply can be continued when there is no possibility of high temperature hot water discharge. For this reason, since possibility of becoming hot water supply stop can be made low, a user's convenience and safety can be made compatible.

  In this embodiment, even if it is determined that there is a mismatch in the first failure determination process, if there is no possibility of high-temperature hot water, the user is not immediately notified of the failure, and in step S18 Only when it is determined by the third failure determination process that the remaining hot water temperature sensor 18 has a definite failure, the process proceeds to step S19 to notify the user of the failure. Thereby, in the case of a minor failure with no danger such as a temporary abnormality of the remaining hot water temperature sensor 18, notification of the failure to the user is avoided, so that the troublesomeness of the user can be reduced. it can.

  FIG. 3 is a flowchart of a failure determination process for maintenance inspection executed by the control device 24 in the first embodiment of the present invention. Hereinafter, with reference to FIG. 3, a case where the failure determination process for maintenance inspection (fourth failure determination process) is executed on the hot water supply pipe 10 side will be described as a representative. Is the same.

  When one of the water supply temperature sensor 20 and the hot water supply temperature sensor 21 fails, the first and second failure determination processing described with reference to FIG. 2 cannot determine which is broken. However, when repairing, it is necessary to specify the failure location. In such a case, it is possible to determine which of the water supply temperature sensor 20 and the hot water supply temperature sensor 21 has failed by executing a fourth failure determination process described below.

  In the fourth failure determination process, hot water is supplied with the mixing valve 14 fully opened, and hot water supplied from the hot water storage tank 2 is allowed to flow into the hot water supply pipe 10. In order to prevent the danger at that time, the fourth failure determination process is executed only when a repair engineer such as a serviceman performs a predetermined special operation that is never performed by a general user. It has become so. Examples of the special operation include an operation of simultaneously pressing and holding a plurality of buttons such as a hot water supply temperature button, a stop days button, and a hot water supply amount button provided on the remote controller 26 for about 5 seconds. Alternatively, a means for accepting a special operation may be provided in the control device 24 instead of the remote control 26.

  When the special operation is performed in step S21 of FIG. 3, the process proceeds to step S22, and hot water supply to the hot water supply pipe 10 is started. After the hot water supply is started, the process proceeds to step S23, and the mixing valve 14 is controlled to the hot water side fully open state. Subsequently, the process proceeds to step S <b> 24, and processing for determining whether the detected temperature of the remaining hot water temperature sensor 18 matches the detected temperature of the hot water supply temperature sensor 21 is performed. When the mixing valve 14 is fully open, only hot water supplied from the upper part of the hot water storage tank 2 through the hot water source pipe 9 flows into the hot water supply pipe 10, so if the hot water temperature sensor 21 is normal, the hot water temperature sensor 21. The detected temperature should correspond to the detected temperature of the remaining hot water temperature sensor 18. In step S24, the control device 24 determines that the absolute value of the difference between the detected temperature of the remaining hot water temperature sensor 18 and the detected temperature of the hot water supply temperature sensor 21 exceeds a predetermined allowable temperature difference (for example, 10 ° C.) for a predetermined allowable time. When it continues over (for example, 5 seconds), it determines with the detected temperature of the hot water supply temperature sensor 21 being inconsistent with the detected temperature of the remaining hot water temperature sensor 18. FIG. In this case, the process proceeds to step S27, the hot water supply is stopped, and the failure is notified by a method such as displaying an error on the remote controller 26 or the like. In this case, it can be determined that the hot water temperature sensor 21 is out of order. In step S27, a notification that the hot water supply temperature sensor 21 is out of order may be given.

  On the other hand, in step S24, the state in which the absolute value of the difference between the detected temperature of the remaining hot water temperature sensor 18 and the detected temperature of the hot water supply temperature sensor 21 exceeds a predetermined allowable temperature difference continues for a predetermined allowable time. Is not accepted, the process proceeds to step S25 to determine whether or not the elapsed time from the start of hot water supply has reached a predetermined time (for example, 1 minute), and the elapsed time from the start of hot water supply has reached the predetermined time. If not, the determination in step S24 is performed again. Even after the predetermined time has elapsed since the start of hot water supply, the state where the absolute value of the difference between the detected temperature of the remaining hot water temperature sensor 18 and the detected temperature of the hot water temperature sensor 21 exceeds the allowable temperature difference continues beyond the allowable time. When it is not recognized that the temperature is detected, it is determined that the detected temperature of the hot water supply temperature sensor 21 and the detected temperature of the remaining hot water temperature sensor 18 are the same. Then, it transfers to step S26 and stops hot water supply. In this case, it can be determined that the hot water supply temperature sensor 21 has not failed. In this case, when it is determined in the past that Steps S14 and S17 in FIG. 2 are not consistent, it can be determined that the feed water temperature sensor 20 is in failure. In addition, you may alert | report that the feed water temperature sensor 20 is out of order in step S26.

  In the first failure determination process (step S14) in the embodiment described above, it is determined whether or not the calculated hot water temperature and the detected temperature of the hot water temperature sensor 21 match, but the set temperature (target temperature) and the hot water temperature are determined. A match / mismatch with the temperature detected by the temperature sensor 21 may be determined.

  In the above-described embodiment, the case where hot water is supplied from the hot water supply pipe 10 side to detect a failure of the remaining hot water temperature sensor 18, the hot water temperature sensor 20, and the hot water supply temperature sensor 21 has been described as a representative. The same can be done for the case where the remaining hot water temperature sensor 18, the hot water temperature sensor 20, and the bath hot water temperature sensor 22 are detected to malfunction.

  Further, in the above-described embodiment, the hot water storage type water heater using the hot water storage tank 2 as a hot water source has been described as an example. However, the present invention provides a heating means for generating hot water using a heater, a heat pump, solar heat, or the like. The present invention is also applicable to a hot water supply device that supplies hot water from this hot water source to the mixing valve.

DESCRIPTION OF SYMBOLS 1 Tank unit 2 Hot water storage tank 3 Heat pump unit 4, 5, 6 Water supply piping 7, 8 Heat pump circulation piping 9 Hot water source piping 10 Hot water supply piping 11 Bath piping 12 Pressure reducing valve 13 Bypass valve 14 Mixing valve (hot water supply)
15 Mixing valve (bath)
16 Check valve 17 Relief valve 18, 19 Remaining hot water temperature sensor 20 Hot water temperature sensor 21 Hot water temperature sensor 22 Bath hot water temperature sensor 23 Heat pump circulation pump 24 Controller 25 Communication line 26 Remote control

Claims (6)

A mixing valve capable of mixing the water supplied from the water source and the hot water supplied from the hot water source and changing the mixing ratio thereof;
Water source temperature detecting means for detecting the temperature of water supplied from the water source;
Hot water source temperature detecting means for detecting the temperature of hot water supplied from the hot water source;
Hot water supply temperature detection means for detecting the temperature of hot water flowing out of the mixing valve;
Mixing valve control means for controlling the mixing ratio of the mixing valve so that the temperature of the hot water flowing out of the mixing valve becomes a target temperature;
Based on the temperature detected by the water source temperature detecting means, the temperature detected by the hot water source temperature detecting means, and the mixing ratio information of the mixing valve, the calculated temperature of hot water flowing out from the mixing valve Calculating hot water supply temperature calculating means for calculating
A first failure determination means for performing a first failure determination process for determining whether the temperature detected by the hot water supply temperature detection means and the temperature calculated by the calculated hot water supply temperature calculation means or the target temperature are matched / mismatched; ,
When it is determined that the first failure determination processing does not match, the temperature detected by the water source temperature detection means and the hot water supply temperature detection means are detected after the mixing valve is controlled to be in a fully open state on the water side. Second failure determination means for performing a second failure determination process for determining whether the temperature matches or does not match,
A water heater equipped with. If it is determined to match in the second failure determination process, hot water supply continues,
The hot water heater according to claim 1, wherein hot water supply is stopped when it is determined that there is a mismatch in the second failure determination process.   A third failure determination for determining whether or not the number of times the second failure determination processing has been executed within a predetermined period in the past has reached a predetermined number when it is determined to match in the second failure determination processing; The water heater according to claim 1 or 2, further comprising third failure determination means for performing processing. If it is determined that they match in the second failure determination process, it is determined that the hot water source temperature detecting means has a failure or a failure,
4. Any one of claims 1 to 3, wherein when the second failure determination process determines that there is a mismatch, the water source temperature detection unit or the hot water supply temperature detection unit determines that there is a failure or a failure. The listed hot water heater. A receiving means for receiving a predetermined special operation;
When the special operation is performed on the receiving means, the mixing valve is controlled to be in a hot water side fully open state to supply hot water, and the temperature detected by the hot water source temperature detecting means and the hot water temperature detecting means are detected. A fourth failure determination means for performing a fourth failure determination process for determining a match / mismatch with the measured temperature;
A water heater according to any one of claims 1 to 4.   The hot water supply device according to any one of claims 1 to 5, further comprising a notification unit that notifies a determination result of the failure determination process.

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