... 24/7 300L 500L 1000L Split Pressurized Solar Water Heater Split pressurized Type composite:solar collector+storage tank+ ... the set valve, controller starts the circulation pump automatically. 3. The circulation pump makes heat-conducting liquid circulate ... ,optionalHeat exchanger materialCopper, stainless steel, optionalFree components:Electric heater, Magnesium rod, T/P valve, Pressure reducing valve ...