solar water heater, pressurized, easy installation, economical, save money, ... solar water heaterSG-S serials is Thermosyphon solar water heater, That is a kind of solar water heating ... is no need of pump to push the fluid and no need of pipeline between the collector and ... 5°C per day7) Optional accessories: assistant tank, electric heater, reflector ,automatic inlet water valve, Magnesium anode, ect. ...