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

September 20, 2022

A furnace is almost always a background player at home, keeping you warm in the cold winter months. It frequently won't be noticed until a malfunction appears.

One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to learn the symptoms of a cracked heat exchanger and what you should do if you believe that might 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 moves throughout the air ducts. It typically does this with 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 getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its key role, it shouldn't come as a surprise that a damaged heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.

For that reason, never run your heating if you suspect you're dealing with a cracked heat exchanger, as doing so could make the whole family ill. Contact an HVAC professional right away if you think your furnace has a cracked heat exchanger that needs to be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: Cracks in the heat exchanger can cause your furnace to switch off.
  • Unusual Smells: If the air escaping your furnace has an intense chemical smell, it could be evidence gas is seeping 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 recognize health problems: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm should go off or household members might start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unwell, leave the home immediately and then call for help.
  • Soot: If you spot black sooty buildup on the exterior of your furnace, it’s another sign something could be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Tomball right away so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

However, the good news is that heat exchangers are generally covered by the warranty. You’ll want to check the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it still may significantly lower 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 consistent furnace maintenance. Furnaces work the best when they work efficiently. Contacting a skilled professional to check your furnace for worn-out parts, dirty filters and other potential 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 ideal 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 harder to complete its job. And the harder your furnace needs to run, the more deterioration parts like the heat exchanger will experience.