| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive heat pump type water heater capable of preventing an inflow of cold water to a lower part of a hot water storage tank during antifreezing operation by eliminating connection between a heat pump going passage pipe and a water supply pipe, simplifying a circuit, capable of preventing freezing of a functional component and piping and preventing decline in hot water temperature within the hot water storage tank. <P>SOLUTION: The heat pump type water heater includes: a heat pump unit heating water by a water heat exchanger; a hot water storage tank unit having the hot water storage tank; and a hot water circulation passage comprising a hot water outward passage for sending hot water from the heat pump unit to an upper part of the hot water storage tank and a hot water return passage for sending hot water from the bottom of the hot water storage tank to the heat pump unit. The heat pump type water heater further includes: a circulating pump provided in the hot water return passage; and a flow passage switching device having a first switching position making the hot water going passage communicated with the hot water return passage and a second switching position making the hot water going passage communicate with the hot water return passage without the hot water storage take interposed therein. When a water temperature of the hot water circulation passage or an outside air temperature reaches a predetermined value or lower, the flow passage switching device is switched to the second switching position and the circulating pump is operated. <P>COPYRIGHT: (C)2011,JPO&INPIT |
