... 1)Heating:Outdoor air temp:20°C/15°C,water tank water temperature from15°C heating to 55°C;(2)Heating: ... against freezing, compressor high-pressure compressor, high and low voltage protection, compressor overtemperature, compressors flow, power supply phase sequence,ensure unit works in hash ... 4. Three in One : Heating, Cooling and Sanitary Hot Water Heat pump water heater with Sanyo scroll compressor