To improve durability of a compressor for a heat pump hot water feeder.

The heat pump hot water feeder comprises a hot water feed circuit where a compressor 1, a refrigerant to water heat exchanger 2, a pressure reducing device 3, and an evaporator 4 are interconnected, in the order, a hot water feed circuit where a hot water storage tank 5, a circulation pump 6, and the refrigerant to water heat exchanger 2 are interconnected, in the order, a temperature detector 8 to detect the hot water temperature at the outlet of the refrigerant to water heat exchanger of the hot water feed circuit; a number-of-revolutions control means 11 to control the number of revolutions of the circulation pump based on a signal from the temperature detector; and an operation controller 13 to control the number of revolutions of the circulation pump such that, during a starting of operation, a hot water temperature is adjusted to a value lower than the set temperature of a hot water temperature and thereafter, it is adjusted to the hot water temperature set temperature. During rise at an operation starting time, the abnormal increase of the pressure and discharge temperature of the compressor is prevented from occurring and durability is improved.