What are typical symptoms of an oil forced air furnace with a hole in the heat exchanger?

In an oil forced air furnace, a hole in the heat exchanger can lead to a significant issue as it allows combustion gases to escape into the airflow. This can result in soot production, which can then become evident in the system's registers. Odors, particularly those associated with burnt fuel or incomplete combustion, are also a direct symptom of compromised heat exchange efficiency. The presence of soot and these odors indicates not only potential inefficiency in operation but also potential health risks, as these combustion gases can be harmful if inhaled.

Other symptoms, while they might seem relevant, are not the primary indicators of a hole in the heat exchanger. Increased noise levels may suggest mechanical issues, overheating could indicate problems with the thermostat or blower, and higher energy bills usually stem from inefficiencies over time rather than an immediate symptom of a hole. Thus, the presence of soot and odors is a clear and direct indication of the combustion process being affected by a breach in the heat exchanger.