The Plieger wireless Quebec On/Off thermostat (white) is a wireless thermostat, meaning that no thermostat wire is required. The clock thermostat sends the current room temperature to the corresponding receiver, which you connect to your central heating boiler. After that, the boiler takes care of reaching the desired room temperature that you have programmed. The clock thermostat is suitable for most central heating boilers and district heating systems when connected to a 24V control valve. Please note: You need to provide power to the corresponding receiver. You can do this with a connection cable (not included). The thermostat cannot modulate. Batteries are not included. Please check before purchasing whether the Quebec wireless On/Off clock thermostat is compatible with your brand of boiler.