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

September 20, 2022

A furnace is often a background player in your home, keeping you warm across the cold winter months. It frequently doesn’t get noticed until something goes wrong.

One cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the symptoms 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 inside your furnace to the air that circulates inside the system. It typically handles this through coils or tubes that heat the air while functioning as a barrier to keep byproducts created in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its important role, it isn't surprising that a broken heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to be distributed across your home.

For that reason, don't ever use your furnace if you suspect it has a cracked heat exchanger, as this could make your entire family ill. Reach out to an HVAC professional immediately if you believe your heating 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 shut off.
  • Odd Smells: If the air coming out of your furnace has a strong chemical odor, it could be a sign gas is slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm goes off or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm could go off or family members could struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unwell, exit the home right away and then call for help.
  • Soot: If you find black sooty accumulating on the exterior of your furnace, it’s another sign something might be seriously wrong.

What You Should Do if a Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Houston right away so they can take a look at your system and, if required, handle a furnace heat exchanger replacement. Costs will vary 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 regularly included in the warranty. It's a good idea to confirm the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it still may significantly reduce 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 through routine furnace maintenance. Furnaces work the best when they run efficiently. Hiring a skilled professional to check your furnace for broken-down parts, clogged 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 replaced 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 dragging air through a clogged filter makes the entire furnace work harder to do its job. And the harder your furnace has to work, the more wear and tear parts like the heat exchanger will endure.