| 摘要 |
PROBLEM TO BE SOLVED: To prevent execution of an operation under a state that a hot water tapping temperature does not reach a target hot water tapping temperature with low boiling performance, for a long time.SOLUTION: A heat pump type water heater includes a refrigerant circuit constituted by successively connecting a compressor, a water heat exchanger for heating hot water, an electric-operated valve, and an air heat exchanger, and a boiling circuit constituted by successively connecting the water heat exchanger, a tank and a pump for supplying the hot water from the tank to the water heat exchanger. A control part of the heat pump type water heater determines starting of a defrosting operation when a flow rate in the pump is a prescribed pump flow rate F or less, and a state that the temperature difference between the hot water tapping temperature and the target hot water tapping temperature is a prescribed hot water tapping temperature difference &Dgr;Tw or more, is continued for a prescribed pump determination time ta. |
