Fresh air needed? When you ventilate after cooking or drying laundry, you no longer need to remember to turn down your heating. The door/window contact is linked to the radiator thermostat and thinks for you. It communicates open windows and doors to the radiator thermostat via your Bosch Smart Home Controller. This can then lower the heating temperature to a value you set. This way, you optimize your heating costs with energy-saving ventilation - and all automatically.