Heat pump water heater

A heat pump water heater, comprising:

• a refrigerating cycle in which a compressor, a four-way valve that switches a flow direction of a refrigerant, a water heat exchanger that performs heat exchange between said refrigerant and water, an expansion mechanism that adjusts a flow rate of the refrigerant and decompresses, and an air heat exchanger that performs heat exchange between the air and the refrigerant are sequentially and circularly connected by a pipeline;
• a water circuit in which said water heat exchanger, a hot water tank that reserves water heated by said water heat exchanger, and a pump are sequentially and circularly connected by a pipeline;
• a water channel pipeline disposed in a lower stage of said air heat exchanger;
• a path switching valve disposed in the water circuit between said pump and said water heat exchanger;
• a bypass circuit connected between said path switching valve and an inlet of said water channel pipeline and connecting an outlet of said water channel pipeline to the water circuit between said path switching valve and an inlet of said water heat exchanger;
• and
• a control portion that executes switching control of said four-way valve and said path switching valve, wherein
• said control portion switches a flow direction of the refrigerant in said refrigerating cycle by switching said four-way valve on the basis of predetermined information during defrosting operation and allows high-temperature water in said hot water tank to flow through the water channel pipeline of said air heat exchanger via said bypass circuit by switching said path switching valve.