The herz Mini  design - thermostatic head M28 x 1.5 with zero setting has a liquid sensor (hydrosensor).
It regulates the room temperature between a set value range of 6 and 30°C. The frost protection protection is at approx. 6 °C. This prevents the heating pipes from freezing and bursting. Due to the zero position, the thermostatic valve is shut off and the frost protection is overrided. The marked comfort setting \"3\" corresponds to about a room temperature of 20 °C and represents an optimal of comfort, energy saving and heating comfort.