| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a heat pump water heater capable of suppressing accumulation of scale when heat pump operation is stopped. <P>SOLUTION: When heating operation is stopped, scale generation prevention operation is performed. The scale prevention operation is operation to stop a compressor in a refrigerating cycle, then continue operation of a pump in a hot water supply circuit until a certain time passes, make water made to flow out from a water outlet of a water refrigerant heat exchanger flow from a bypass return port to a tank via bypass piping for bypassing the tank, and stop the operation of the pump of the hot water supply circuit after a certain time passes. In the scale generation prevention operation, the certain time is set to become longer as target hot water delivery temperature of the water refrigerant heat exchanger during the heating operation increases. <P>COPYRIGHT: (C)2011,JPO&INPIT |
