HEAT PUMP TYPE WATER HEATER

摘要

PROBLEM TO BE SOLVED: To detect the trouble of a circulation pump without installing a special flow water switch or a flow sensor in the heating circulation water circuit of a heat pump type water heater. SOLUTION: When a temperature obtained by deducting the forward temperature TH2 of heating circulation water detected by a thermister 14 detecting the forward temperature of the heating circulation water from a refrigerant temperature TH1 detected by a thermister 16 detecting the refrigerant temperature is larger than a temperature differenceΔtmp including heat exchange rate between a refrigerant and the heating circulation water caused when the pre-set heating circulation water circulates normally, and it is detected that its state continues for a specified T hours, a microcomputer M (control means) installed in the water heater determines that the circulation pump 9 fails. COPYRIGHT: (C)2004,JPO&NCIPI