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

September 20, 2022

A furnace is usually a background player at home, ensuring you're warm during the cold winter months. It often doesn’t get noticed until a malfunction appears.

One root cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s worthwhile to learn the symptoms of a cracked heat exchanger and what to do if you are worried that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger transfers heat from the combustion chamber inside your furnace to the air that flows throughout the air ducts. It usually does this using coils or tubes that heat the air while functioning as a barrier to keep the gasses formed in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its important role, it shouldn't come as a surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to flow across your home.

For that reason, do NOT use your heater if you think there's a crack in the heat exchanger, as doing so could make the whole family ill. Call an HVAC professional immediately if you are worried your heater has a cracked heat exchanger that needs to be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger can cause your furnace to switch off.
  • Unusual Smells: If the air leaving your furnace has an intense chemical odor, it could be evidence gas is leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm could go off or household members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel unwell, leave 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 might be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, call a professional well versed in furnace installation Cedar Rapids right away so they can inspect your system and, if needed, start a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are regularly covered by the warranty. You should check the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it can significantly reduce your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

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

It’s also helpful to inspect your furnace filters every few months – it’s ideal some filters be changed 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 drawing air through a clogged filter makes your entire furnace work harder to accomplish its job. And the harder your furnace has to work, the more deterioration parts like the heat exchanger will endure.