Cracked Combustion Chamber Oil Furnace

If a heat exchanger is cracked air forced into the combustion chamber will cause the oxygen reading in the furnace s exhaust to rise to abnormal levels.

Cracked combustion chamber oil furnace.

If you have been told your furnace s heat exchanger is cracked ask the tech to show you the exhaust s oxygen readings when. Often when cracks are present in a heat exchanger soot from the combustion process will seep through and discolor the metal. It has been taken care of well over it s 30 years of service. The result will be a buildup of soot around the crack site and or spots that are a darker color than the rest of the metal.

This trips a safety switch and shuts down the furnace. An improperly maintained oil burner that repeatedly becomes locked out and manually reset can flood the chamber with heating oil. A cracked heat exchanger allows air from the furnace blower to interfere with the flame causing it to flutter or even roll out. The easiest way i have found to find a crack in the combustion chamber of an oil furnace is to pull the blower turn the lights out turn the furnace on if it has a crack or hole in the combustion chamber i guarantee you will see it.

April 17 2019 the combustion chamber of an oil fired furnace will eventually collapse and require replacement. Turn off the furnace and open it for inspection using your furnace s manual as a guide. Step 2 look for cracks or rust spots in the metal walls of the combustion chamber and heat exchanger using a flashlight if necessary. Our furnace is an esso ultramatic hot air furnace.

Also look for sooty discoloration which might appear if combustion byproducts are passing through barely visible cracks. The oil company we deal with has told us that the chamber is no longer made and a wet pack will be needed to seal the crack that has developed on the right side. A cracked heat exchanger similar to a clogged exhaust or chimney prevents the combustion gases from properly venting out the furnace and results in an internal pressure irregularity that can cause a flame roll out. This would also necessitate chamber replacement.

Beware of an unethical technician who finds a crack with a camera on a furnace that seems to be running just fine.