Water heater

摘要

[Object] To obtain a water heater that is capable of delivering hot water at a higher temperature, while suppressing an increase in the condensing pressure of a refrigerant. [Solution] A refrigerant circuit includes a compressor 2 that compresses a refrigerant, the capacity of the compressor 2 being variable; a refrigerant/water heat exchanger 12 that exchanges heat between the refrigerant and water; a decompression device 4 that decompresses the refrigerant by opening degree adjustment; and an evaporator 5 that evaporates the refrigerant by heat exchange, and the compressor 2, the refrigerant/water heat exchanger 12, the decompression device 4, and the evaporator 5 are connected by pipes. A refrigerant circuit further includes a water supply pump 7 that forms a flow of water passing through the refrigerant/water heat exchanger 12, the water flow rate of the water supply pump 7 being variable; water inlet temperature detection means 8 for detecting a water inlet temperature of the water flowing into the refrigerant/water heat exchanger 12; water outlet temperature detection means 10 for detecting the water outlet temperature of the water flowing out of the refrigerant/water heat exchanger 12; and a controller 15 that performs fixed control for the capacity of the compressor 2 when the water inlet temperature is determined to have reached a preset first temperature, and that performs variable control for the water flow rate of the water supply pump 7 so that the water outlet temperature is made equal to a second temperature, are provided.