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

September 20, 2022

A furnace is almost always a background player for your home, keeping you warm during the cold winter months. It often doesn’t get noticed until something goes wrong.

One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the evidence of a cracked heat exchanger and what you can do if you believe that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps transition heat from the combustion chamber of your furnace to the air that circulates through the ventilation. It typically does this with coils or tubes that heat the air while serving as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its key role, it isn't surprising that a damaged heat exchanger can be hazardous. A damaged heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.

For obvious reasons, do NOT turn on your heating if you believe you're dealing with a cracked heat exchanger, as doing so could make your entire household sick. Call an HVAC professional immediately if you are worried your heater has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace shuts off: A crack in your heat exchanger could cause your furnace to shut off.
  • Odd Smells: If the air escaping your furnace has an intense chemical scent, it could be evidence gasses are slipping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm initiates or you notice symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm should go off or household members may start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the 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 accumulating around 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 pro well versed in furnace installation Pocatello as soon as possible so they can take a look at your system and, if needed, handle a furnace heat exchanger replacement. Costs often vary depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

However, the good news is that heat exchangers are regularly protected by the warranty. You should review the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it still may significantly shrink your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the most convenient ways to avoid problems in your furnace overall is via regular furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Hiring a trained professional to examine your furnace for old parts, clogs in the air filters and other common problems can keep you from getting a big bill later on.

It’s also helpful to take a look at your furnace filters every few months – it’s recommended some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters are not 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 strain components like the heat exchanger will sustain.