A method and apparatus are provided to control the burning of a lean hydrocarbon containing gas stream under stable conditions using a combination of control logic and hardware. Temperature within the combustor is controlled by using a plurality of staging valves that adjust the amount of oxygen and auxiliary fuel supplied to the combustor burner. Oxygen level is controlled by using actuated butterfly valves that control the flow of primary air to the combustor. The system has pressure control valves for anticipating and compensating for pressure changes and resulting air flow changes as well as temperature monitors and transmitters for anticipating and correcting temperature drops.