| 摘要 |
PROBLEM TO BE SOLVED: To provide a water heater capable of preventing occurrence of a failure in water circulation due to air entered into a circulation pump.SOLUTION: The water heater includes: a hot water storage tank 10 for storing a heating medium; a heat pump unit 3 for heating the heating medium supplied from the hot water storage tank 10 through a forward path by a water/refrigerant heat exchanger 3c by using a circulation pump 3a and returning the heating medium to the hot water storage tank 10 through a return path; a drain passage including a release valve 91 to be opened when pressure in the hot water storage tank reaches a predetermined pressure and capable of draining the heating medium drained from the release valve 91 to the outside; a heating route opening valve 8 for communicating the forward path to the drain passage; and a controller 100 which monitors a circulation flow rate of the heating medium between the water storage tank 10 and the heat pump unit 3, and when the circulation flow rate to be monitored is a first predetermined flow rate or less, determines circulation abnormality, opens the heating route release valve 8, and drains the heating medium. |
