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

September 20, 2022

A furnace is usually a background player in your home, helping keep you warm in the cold winter months. It frequently isn't 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 can do if you are worried that may be 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 moves inside the ventilation. It usually does this via coils or tubes that heat the air while acting as a barrier to keep gas produced in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its key role, it isn't surprising that a broken heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow through your home.

For this reason, don't ever use your furnace if you think it has a cracked heat exchanger, as doing so could make your entire household sick. Contact an HVAC professional right away if you believe your furnace has a cracked heat exchanger that needs repair.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace shuts off: A cracked heat exchanger could cause your furnace to turn off.
  • Strange Smells: If the air leaving your furnace has a strong chemical scent, it may be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm initiates or you feel symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm may go off or household members could experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel sick, leave the home immediately and then call for help.
  • Soot: If you notice black sooty collecting on the exterior of your furnace, it’s another sign something may be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, contact a professional experienced in furnace installation Carson City as soon as possible so they can examine your system and, if needed, handle a furnace heat exchanger replacement. Costs often differ 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 often covered by the warranty. You’ll want to check the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it can significantly lower your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to prevent a problem in your furnace overall is through routine furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a trained professional to inspect your furnace for worn-out parts, dirty filters and other common problems can help you avoid getting a big bill later on.

It’s also helpful to review 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 aren't connected to the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work longer to complete its job. And the harder your furnace has to work, the more strain pieces like the heat exchanger will sustain.