Split Solar Water Heating System use electric pumps, valves, and controllers to circulate water or other heat-transfer fluids through the collectors. They are usually more expensive than compact solar water heater. Split solar water heating system are generally easier to retrofit than compact solar water heater because their storage tanks do not need to be installed above or close to the collectors

Open-loop Split Solar Water heating system

These systems use pumps to circulate household water through the collectors. This design is efficient and lowers operating costs but is not appropriate if your water is hard or acidic because scale and corrosion will quickly disable the system. Open-loop active systems are popular in regions that do not experience subzero temperatures. Flat plate open-loop systems should never be installed in climates that experience sustained periods of subzero temperatures. They may be installed in mild climates that experience occasion subzero temperatures, but freeze protection must be implemented.