1. Completely isolate water and power, safe and reliable use 2. Small main unit, convenient for installing, water tank can be equipped flexibly, meet the requirements of different clients. 3. Apply built-in heat exchanger, water pipe isn¡¯t installed with coppet pipe, the main unit and water tank is only required to be connected with water pipe, compulsive heat exchange between medium and water, therefore, it features higher heat exchange efficiency, better stability and longer service life. 4. Apply microcomputer controller, users can freely set according to the actual requirements. 5. It is compatible with solar energy. Save energy, prevent hot water shortage in rainy and shade day, assure normal use or hot water