1.   When the temperature of the heat collector reaches the set value, the controller shall start the  circulation pump automatically.
2.   The circulation pump makes heat-conducting liquid circulate automatically.
3.   The heat -conducting liquid transfers heat to water by the heat exchanger in the water tank.
4. In Case the temperature of the circulation pump does not reach the set value, the circulation pump shall be stop working automatically.
5.   In Case the temperature of the water tank does not  reach Tmax, then start the electrical heater.