Systems and methods for operating a gas-fired appliance such as a gas-fired cooking grill are provided. An embodiment of the system includes a gas burner for heating a chamber of the gas-fired appliance. The system includes a first valve associated with the gas burner to control a gas flow to the gas burner. The system includes a second valve configured to controllably supply gas to the gas burner via the first valve. The second valve is automatically adjustable based on a desired temperature of the chamber and an actual temperature of the chamber.