A sensor surrogate (120) for causing a heating, ventilating, and air conditioning (HVAC) system (110) to maintain a desired room temperature, contains a temperature sensor (122) for determining an actual room temperature and logic embodied on at least one non-transitory computer readable medium (130). The logic (130) is configured to perform the steps of: calculating a current low temperature that is lower than a pre-programmed HVAC system temperature and providing the HVAC system with a first signal that represents the calculated current low temperature, if the desired temperature is above the pre-programmed HVAC system temperature; and calculating a current high temperature that is above the pre-programmed HVAC system temperature and providing the HVAC system (110) with a second signal that represents the calculated current high temperature, if the desired room temperature is below the pre-programmed HVAC system temperature.