A system and method is presented for providing failsafe control in a control system used for receiving and controlling various object or medium properties in a heating, ventilating or air conditioning system. The control system comprises an HVAC controller, configured to receive failsafe data indicative of a safety related property of an object or medium, and to generate a state indicative of a connection status of a failsafe detector with respect to the HVAC controller. The control system further comprises a non-volatile memory, operably coupled to the HVAC controller and configured to store a connection indication indicative of a connection status of the failsafe detector with respect to the HVAC controller, wherein the HVAC controller is configured to generate a control signal based on satisfaction of a predetermined relationship between the generated state and the stored connection indication.