Abstract: A feed forward system coupled with a feed back system is used to control the efficiency of combustion of fuel in a furnace. The feed forward system has sensors to measure the fuel flow rate and the quality of the fuel. The measurement of the sensors is used to calculate the theoretical oxygen flow rate needed to combust the fuel. The theoretical oxygen flow rate and an excess oxygen level are used to determine the actual air flow rate, which is used to control the air input to the furnace. The feedback system has a sensor to detect combustibles near the exhaust of the furnace. The measurement of the combustible sensor is used to control the excess oxygen level. In a preferred embodiment, another sensor, an oxygen sensor, is placed near the exhaust of the furnace. The oxygen sensor provides a dynamic check on the actual amount of excess oxygen level within the furnace. Finally, the oxygen sensor is also used as a safety device in providing redundancy to the combustible sensor.