| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a heat pump water heater preventing supplied water from boiling in a hot water supply heat exchanger while preventing releasing of refrigerant heat in the hot water supply heat exchanger during defrosting operation. <P>SOLUTION: The heat pump water heater is equipped with a hot water supply circuit 17, a hot water supply pump 18, a heat pump cycle 2, and a control device 3. A detecting means 19 is provided for detecting information regarding a boiling state of the supplied hot water in the hot water supply heat exchanger 22. When defrosting operation is performed in an evaporator 24 of the heat pump cycle 2, the control device 3 increases the valve opening of a variable pressure reducing mechanism 23 of the heat pump cycle 2 to larger than before the defrosting operation, and stops the hot water supply pump 18 when it is determined that the supplied hot water does not boil from the information obtained by the detecting means 19. <P>COPYRIGHT: (C)2009,JPO&INPIT |
