Performed the level 2 furnace cleaning. Burners and flame sensor are clean. Heat exchanger is rusting in spots. Combustion readings were okay. No CO detected in the air. Drain is clear. High limit passed the safety check. Heat rise was 45°. Venter motor sounds very worn on initial start up. Average life of unit is 12-15 years. Furnace is currently 14 years old. Future life expectancy is hard to say. Dan Fox will be evaluating the unit to give options.