How are the heat exchangers in the furnaces inspected?
Between 0% to 20%, depending upon efficiency rating, of a forced air gas furnace heat exchanger can be visually examined. A deteriorating heat exchanger will often exhibit accumulated particles of rust in the burner compartment and flame distortion when the furnace blower is activated. A Carbon Monoxide test is not usually performed because they can be unreliable during certain temperature conditions. If there is any mention of the heat exchanger in your inspection report get it serviced before closing! Heat exchangers are not implied to be free of defects. The temperature extremes make heat exchangers unpredictable.
