Abstract: A flue gate device operated by a solenoid whose energy comes from any outside source, which energy is controlled by the furnace burner control of the furnace to which it is attached. The pull of the solenoid is resisted by a spring which will restore the flue gate to an open position when the solenoid is deenergized or in case of an electrical failure in the flue gate device itself. Through relay switches, the solenoid is deenergized when the furnace burner is energized, and the solenoid is energized when the burner is deenergized, thus enabling a "fail-safe" condition, which enables the furnace to function completely free of the flue gate device.