Exhaust air systems such as a bath fan generate a vacuum in the room, as long as not enough air can flow in. As soon as a space-dependant combustion site (e.g. Gas herms) in the room, dangerous exhaust gases can be removed from it and spread in the room. By using the KGS 116 cable exhaust control, an exhaust air system can only be used if the space-dependant combustion system is switched off. The control unit is connected to the potential-free contact (normally open contact) of the gas therms with a cable. As soon as the combustion starts and the contact closes, the exhaust system (e.g. Bath fan) is switched off. This text is machine translated.