Your home’s furnace provides warmth and comfort to your residence however, it can encounter various issues necessitating repair, part replacement, and general overall upkeep. Among these issues, a cracked heat exchanger can be quite hazardous and should be repaired by an HVAC trained professional as soon as you become aware of it.

Signs of a Cracked Heat Exchanger

Your furnace’s heat exchanger heats and cools air as you use your furnace. These temperature changes over long periods of time can weaken the metal that the heat exchanger is made of causing cracking. There are several signs that your furnace may have a cracked heat exchanger, including:

  • Strange Noises. When running your furnace, listen carefully to the fan when you shut it off. A noticeable clicking noise could be a sign of a crack to the heat exchanger and should be repaired by a professional.
  • A coating of soot on the inside of your furnace is a sign that it is not running as it should. This type of build-up means your furnace is not burning fuel properly which could mean it has a crack in the heat exchanger.
  • If you notice unpleasant smells like formaldehyde when running your heater (or shortly after it shuts off), this could also be a sign of damage to your furnace’s heat exchanger.
  • Physical Illness. A cracked heat exchanger causes gases to escape which can lead to illness. Common symptoms include nausea, sleepiness, congestion, eye irritation, headaches, and feeling like you have the flu. Your carbon monoxide detectors should notify you of a hazardous leak.

Why A Cracked Heat Exchanger is Dangerous

When your furnace’s heat exchanger is damaged it can release dangerous gases into your home causing the above-described ailments. These gases include nitrous and sulfur dioxide however, carbon monoxide can also be released and is very dangerous in high enough concentrations.


Cracks to your heat exchanger should not be ignored as they not only make your furnace inefficient they can also be a danger to your health. Jackson & Sons can help you with all your furnace repair and maintenance needs. Proudly serving residents of eastern North Carolina contact Jackson & Sons today to learn more.