A housing contains two thermostats which thermostats are interwired so as to enable one thermostat to control a heating operation and the other thermostat to control a cooling operation. The housing contains at least one AC power receptacle coupled to the heating thermostat and one AC power receptacle coupled to the cooling thermostat. In this manner a heater would be plugged into the one receptacle while an air conditioner would be plugged into the other receptacle. The individual thermostats would be set for a temperature heating range being the difference between the settings. The wiring between the thermostats causes the heating thermostat to come on when the temperature falls below the values set. This in turn causes the plugged in heater to operate. When the temperature is above a value set by the heating thermostat, the unit removes power from all AC receptacles. As soon as the temperature rises above a value set by the cooling thermostat, the cooling thermostat causes the associated AC receptacle to be energized thus turning on the air conditioner. The air conditioner will remain on until the temperature falls below the setting, and at this condition, both the heating unit and the air conditioning unit will be off. As soon as the temperature falls below the value set by the heating thermostat, the heater is again turned on. This series of operations continues maintaining the room at a comfortable temperature within a very narrow range which range may be for example between 4 to 10 degrees depending upon the accuracy of the thermostats.