An automatic flue damper is an energy-saving device that closes off or restricts an appliance flue when the appliance is not operating and is in its “off” cycle. It traps residual heat in the heat exchanger after the burners shut off, and prevents the escape of conditioned air up the vent pipe.

Most fuel-gas appliance manufacturers require the installation of a sediment trap. Sediment traps prevent debris from entering the gas controls and causing hazardous malfunctions.