Temperature regulators are used to control heating or ventilation devices in order to maintain a constant ambient temperature. Until the desired ambient temperature is reached, the relay contact is in the 2-1 position and the heating device is switched on. When the set temperature is reached, the contact switches to position 2-8 and the heating device is switched off, or the ventilation device is switched on. A decrease in temperature by the hysteresis value will switch on the heating device again (contacts 2-1 closed) until the set temperature is reached.