GUIDE to CLOSED LOOP SYSTEM for HOT WATER
How the closed loop system works for generating FREE heated hot water.

Systems using pumps should have a control unit. Whenever the solar panel is hotter than the storage tank the solar pump should be on and the system circulating. When the storage tank is hotter than the solar panel the pump will be switched off by the control unit.

The solar pump is used for circulating the flow of the antifreeze between the solar panel and the water storage tank.

It is recommended to install an expansion tank in a closed loop system. This allows the heated fluid (antifreeze) to safely expand, otherwise it could damage the system.