Abstract: A fuel fired, atmospheric water heater has a burner positioned inside a combustion chamber. All combustion air entering the combustion chamber must pass through a damper. The damper is operable to adjust the flow resistance to combustion air entering the combustion chamber. The damper is biased to a closed position such that during non-firing periods of the water heater, the damper significantly reduces the flow rate of combustion air being provided to the combustion chamber reducing standby heat loss. An actuator is in fluid communication with a fuel supply line such that when pressurized fuel is provided to the burner, the pressurized fuel causes the actuator to move the damper to an open position to permit operative combustion air delivery to the combustion chamber during firing periods of the water heater.