The main danger simple solar water heaters face is a chance that water will freeze inside pipes during a cold winter night and damage the piping. To avoid this drainback solar water heater was created. Special thermal sensor detects when it is too cold and stops water pump from pumping water into solar collector. Remaining water drains back to the heat exchange tank thus eliminating the danger to burst pipes. When outside temperature rises, water pump kicks in and start pumping water into solar collector again.
