To provide a heat pump water heater, capable of continuing operation while minimizing the inconvenience to a user even in case of failure of a pressure sensor.
This water heater comprises a compressor 21, a water heat exchanger 22 performing heat-exchange of a refrigerant discharged from the compressor with a hot water supply fluid; a pressure sensor 31 detecting a pressure of the refrigerant flowing out of the heat exchanger 22, and an electronic control unit 30 performing, based on the pressure detected by the sensor 31, high-pressure control of a heat pump cycle so that the temperature difference between the hot water supply fluid flowing into the heat exchanger 22 and the refrigerant flowing out of the heat exchanger 22 is a target temperature difference ΔTo. The electronic control unit 30 performs the high-pressure control for changing the opening of an expansion valve 23 based on the target temperature difference ΔTo with a regulated upper limit. According to this, operation can be continued even in case of failure of the pressure sensor.
MAKI KENICHI
NABENO YOSHIYUKI
| JP2003176957A | 2003-06-27 | |||
| JP2002081771A | 2002-03-22 | |||
| JPH04222349A | 1992-08-12 | |||
| JPH08152204A | 1996-06-11 | |||
| JP2005147437A | 2005-06-09 | |||
| JP2000346447A | 2000-12-15 | |||
| JPH1089782A | 1998-04-10 | |||
| JPH03102141A | 1991-04-26 | |||
| JPH01302082A | 1989-12-06 |