... the world solar water heaterSG-S serials is Thermosyphon solar water heater, That is a kind of solar water heating system that solar ... performance, economy.4) Temperature when exposed to sun without water: 250°C, 2.5 hours to boiling point if ... ) Optional accessories: assistant tank, electric heater, reflector ,automatic inlet water valve, Magnesium anode, ect. 8) 5 years warranty.Product ModelTubes ...