A flow control device for an appliance including a burner and a blower for delivering a pre-mixed mixture of air and gas to the burner includes a flange defining an opening through which the pre-mixedmixture of air and gas flows from an outlet of the blower to the burner. A damper plate is provided in the opening downstream of the blower for increasing a static pressure at the outlet of the blower during ignition of the burner.