Cracked Heat Exchanger: What It Means and What You Should Do Next

September 20, 2022

A furnace is often a background player in your home, keeping you warm across the cold winter months. It frequently won't be noticed until something goes wrong.

One root cause might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to know the symptoms of a cracked heat exchanger and what you can 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 in your furnace to the air that flows through the ventilation. It generally does this with coils or tubes that heat the air while acting as a barrier to keep gas formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its central role, it shouldn't come as a surprise that a broken heat exchanger can be hazardous. Cracks in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow throughout your home.

For this reason, don't ever run your heating if you think it has a cracked heat exchanger, as this could make your entire family ill. Contact an HVAC professional as soon as possible if you think your heating 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.
  • Odd Smells: If the air escaping your furnace has a strong chemical odor, it could be a sign gasses are slipping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you notice symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm may go off or household members may struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel sick, leave the home right away and then call for help.
  • Soot: If you notice black sooty buildup around the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, hire a pro with extensive experience in furnace installation Booneville as soon as possible so they can examine your system and, if necessary, perform a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are often included in the warranty. It's a good idea to review the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it still may significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the easiest ways to prevent a problem in your furnace overall is with regular furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a skilled professional to check your furnace for old parts, dirty filters and other common problems can keep you from getting a big bill later on.

It’s also beneficial to review your furnace filters every few months – it’s recommended some filters be swapped out 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 the entire furnace work longer to complete its job. And the harder your furnace has to work, the more deterioration pieces like the heat exchanger will sustain.