Cracked Heat Exchanger: What That Means and What You can 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 a malfunction appears.

One root cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to learn the signs of a cracked heat exchanger and what to do if you suspect that is 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 circulates through the ventilation. It typically accomplishes this through coils or tubes that warm the air while serving as a barrier to keep gas formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its key role, it shouldn't come as a surprise that a cracked heat exchanger can pose a risk. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.

For that reason, don't ever run your furnace if you believe you're dealing with a cracked heat exchanger, as doing so could make the whole family sick. Reach out to an HVAC professional right away if you believe your heating has a cracked heat exchanger that needs to be repaired.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: Cracks in the heat exchanger could cause your furnace to turn off.
  • Odd Smells: If the air leaving your furnace has an intense chemical scent, it might be an indicator that gas is slipping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm may go off or family members could start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel unwell, exit the home as soon as you can and then call for help.
  • Soot: If you spot black sooty collecting near the exterior of your furnace, it’s another sign something might be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation Moline as soon as possible so they can take a look at your system and, if needed, perform a furnace heat exchanger replacement. Costs often differ depending on the situation, but estimates often hover around $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are regularly protected by the warranty. It's a good idea to review the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it can significantly shrink your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the best ways to avoid problems in your furnace overall is with regular furnace maintenance. Furnaces work the best when they operate efficiently. Hiring a skilled professional to inspect your furnace for broken-down parts, dirty filters and other potential problems can keep you from getting a big bill later on.

It’s also beneficial to take a look at your furnace filters every few months – it’s recommended some filters be swapped out 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 drawing air through a clogged filter makes your entire furnace work more vigorously to accomplish its job. And the harder your furnace has to work, the more deterioration components like the heat exchanger will endure.