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

September 20, 2022

A furnace is almost always a background player at home, helping keep you warm across the cold winter months. It often doesn’t get noticed until something breaks down.

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

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps move heat from the combustion chamber of your furnace to the air that flows throughout the ventilation. It usually handles this with coils or tubes that heat up the air while functioning as a barrier to keep byproducts formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its important role, it isn't surprising that a cracked heat exchanger can pose a risk. Cracks in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow across your home.

For this reason, never run your heater if you think it has a cracked heat exchanger, as doing so could make your entire family ill. Call an HVAC professional as soon as possible if you are worried your furnace has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: A cracked heat exchanger can cause your furnace to switch off.
  • Odd Smells: If the air leaving your furnace has a powerful chemical odor, it may be a sign gas is seeping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm initiates or you feel symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm may go off or family members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unusually tired, get out of the home as soon as you can and then call for help.
  • Soot: If you spot black sooty accumulating near the exterior of your furnace, it’s more evidence something may be seriously wrong.

What You Can 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 Gresham as soon as possible so they can examine your system and, if necessary, handle a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

However, the good news is that heat exchangers are regularly protected by the warranty. You’ll want to review 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 Prevent a Cracked Heat Exchanger in Your Home

One of the best ways to minimize the risk of problems in your furnace overall is via consistent furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Calling a certified professional to check 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 a good idea to take a look at 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 are not part of the heat exchanger itself, the strain of pulling 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 strain components like the heat exchanger will experience.