The heat pump water heater is a way of the heat pump technology in a production hot water .its different from heating way to traditional water heater entirely, is take the air, the water, the solar energy and so on as the low temperature heat source, heats up the domestic water by the electrical energy as the power from the low temperature side absorption quantity of heat, the hot water sends to the user directly through the circulatory system or carries on the small area heating. Has avoided those problems of the traditional fuel oil, fuel gas and electric energy heater, such as the big consumption, the pollution serious, and the high expense .May save 75% of daily use cost, not affected by changes of the weather. It is widely used in school dormitory, hotel, guesthouse, beauty salon, worker dormitory, the bathing pool with constant temperature, the sauna hall, the block of flats, the cosmetology shop, the air source water heater project, the bath center.