... pressurized solar water heater 2.Solar heat pipe pressure collector 3Temperature rise up quickly 4.High efficiency The key of this system is ... degree, 25 degree, 30 degree, 38 degree, 45 degree for flat roof or 0 degree for slope roof. ModelAll glass solar ... can display the temperature, control circulation pump, control electrical heater.2. Electrical heater, which is backup fitting when it is rainy or ...