Cracked Heat Exchanger: What It Means and What to Do Next

September 20, 2022

A furnace is often a background player in your home, helping keep you warm during the cold winter months. It often isn't noticed until something breaks down.

One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to know the symptoms of a cracked heat exchanger and what you should do if you believe that is the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps transition heat from the combustion chamber in your furnace to the air that flows inside the system. It typically accomplishes this through coils or tubes that warm the air while acting as a barrier to keep the gasses produced in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its central role, it shouldn't come as a surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.

For this reason, never turn on your furnace if you believe there's a crack in the heat exchanger, as letting it run could make your entire household sick. Reach out to an HVAC professional immediately if you believe your heater has a cracked heat exchanger that should be repaired.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: A cracked heat exchanger could cause your furnace to switch off.
  • Unusual Smells: If the air leaving your furnace has an intense chemical odor, it could be a sign gasses are slipping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you feel symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm may go off or family members might start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel unusually tired, get out of the home immediately and then call for help.
  • Soot: If you notice black sooty accumulating near the exterior of your furnace, it’s another sign something could be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation Siloam Springs right away so they can examine your system and, if needed, perform a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are generally included in the warranty. You should confirm the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it still may significantly reduce your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the most convenient ways to avoid problems in your furnace overall is through regular furnace maintenance. Furnaces work the best when they run efficiently. Calling a trained professional to examine your furnace for worn-out parts, dirty filters and other common problems can help you avoid getting a big bill later on.

It’s also a good idea to review your furnace filters every few months – it’s recommended some filters be changed every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to the heat exchanger itself, the strain of pulling air through a clogged filter makes the entire furnace work longer to accomplish its job. And the harder your furnace has to work, the more strain components like the heat exchanger will experience.