Freeze protection valve iStop 108, Beulco

The antifreeze valve allows the circuit medium to be drained when its temperature reaches an average value of 3 °C. This prevents ice forming in the circuit of a system, usually with a heat pump, avoiding potential damage to the machine and to the pipes. The version with air sensor allows the system to work in cooling mode, even when the water temperature approaches 3 °C. In these conditions the air sensor kicks in to prevent water drainage.