The basic principle is that the drain-back system empties automatically
You open the drain in a filled bathtub and, thanks to gravity and the gradient, the bathwater drains off automatically.
Our solar collector water now does not flow into the discharge channel, but is collected in the drain-back tank and, if necessary, pumped back into the solar system.
The operation and filling is explained for the pool water heating and not for a solar thermal!
SAFE - LOW-MAINTENANCE - COST-EFFECTIVE