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

September 20, 2022

A furnace is usually a background player at home, helping keep you warm during the cold winter months. It regularly isn't noticed until something goes wrong.

One source could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to know the symptoms of a cracked heat exchanger and what to do if you suspect that is the problem.

What Is a Heat Exchanger in a Furnace?

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

Is a Cracked Heat Exchanger Dangerous?

Thanks to its central role, it’s no surprise that a damaged heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed throughout your home.

For obvious reasons, do NOT run your heating if you think you're dealing with a cracked heat exchanger, as doing so could make the entire household sick. Reach out to an HVAC professional as soon as possible if you think your furnace has a cracked heat exchanger that should be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace switches off: A crack in your heat exchanger could cause your furnace to shut off.
  • Strange Smells: If the air escaping your furnace has a strong chemical scent, it may be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should go off or household members might start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel sick, get out of the home right away and then call for help.
  • Soot: If you find black sooty buildup on the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a professional with extensive experience in furnace installation Newark right away so they can inspect your system and, if required, perform a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are often covered by the warranty. You’ll want to check the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it can significantly reduce your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the most convenient ways to prevent a problem in your furnace overall is through regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Contacting a skilled professional to check your furnace for old parts, clogs in the air filters and other likely problems can help you avoid getting a big bill later on.

It’s also helpful to take a look at your furnace filters every few months – it’s encouraged some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters aren't a part of the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work longer to accomplish its job. And the harder your furnace works, the more deterioration parts like the heat exchanger will sustain.