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

September 20, 2022

A furnace is almost always a background player for your home, ensuring you're warm across the cold winter months. It often isn't noticed until something goes wrong.

One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to know the symptoms of a cracked heat exchanger and what to do if you believe that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger transfers heat from the combustion chamber in your furnace to the air that flows inside the system. It typically handles this with coils or tubes that heat the air while serving 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?

Given its key role, it’s no surprise that a cracked heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to flow throughout your home.

For this reason, don't ever turn on your furnace if you suspect you're dealing with a cracked heat exchanger, as this could make the entire family sick. Contact an HVAC professional right away if you are worried your furnace has a cracked heat exchanger that should 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.
  • Unusual Smells: If the air coming out of your furnace has an intense chemical scent, it could be a sign gasses are leaking through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm goes off or you recognize health problems: 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 unwell, exit the home right away and then call for help.
  • Soot: If you find black sooty collecting near the exterior of your furnace, it’s an indication something could 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 professional well versed in furnace installation Cottonwood right away so they can take a look at your system and, if needed, handle a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates often hover around $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are regularly included in 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 could significantly shrink your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the easiest ways to minimize the risk of problems in your furnace overall is via consistent furnace maintenance. Furnaces offer the most benefits when they work efficiently. Calling a certified professional to check your furnace for broken-down parts, clogs in the air filters and other common problems can help you avoid getting a big bill later on.

It’s also beneficial to review your furnace filters every few months – it’s encouraged 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 works, the more deterioration pieces like the heat exchanger will experience.