Thermosiphon system : Using a thermosiphon solar water heater systems is an excellent way to start saving on your domestic hot water heating bills. The tank must be installed above the collectors, so the thermosiphon phenomenon can occur, circulation water from collector to tank. Advantages: 1. It can operate automatically if connect with intelligent controller. 2. Simple structure, easy plug-in installation, can be installed both on flat and inclined roof, and can be used with an auxiliary electric booster as to provide tot water without sunshine. 3. Superior heat preservation ensured by one-off molding polyurethane foam with thickness 50 65mm. 4. Suitable for camping area, holiday residences. 5. stable and reliable performance, well wind resistance. 6. Meet the mankind healthy bath standard: The material of inner tank is SUS304-2B stainless steel plate; the silicagel ring sealing has a long life against the erosion and it ie not harmful to health.