... Automatic prevent freezing in winter. Heat Pump Three In One Unit:Product Features:1.Applied range:sanitary hot water,heating,cooling ... -friendly refrigerant: R407C .8.Two speed fan motor:further improve unit operation(hot water model)under high ambient temperature.9.Expansion ... wire controller.12.Can set the operating time freely. 13.Unit runs or stop automatically according to water temperature.14.Can ...