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

September 20, 2022

A furnace is often a background player at home, keeping you warm across the cold winter months. It regularly isn't noticed until something goes wrong.

One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to know the symptoms of a cracked heat exchanger and what you can do if you are worried that is 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 air ducts. It usually handles this through coils or tubes that heat the air while serving as a barrier to keep gas created in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its central role, it isn't surprising that a cracked heat exchanger can pose a risk. A crack in the heat exchanger can permit dangerous gasses – including carbon monoxide, which can be lethal – to circulate throughout your home.

For that reason, don't ever turn on your heating if you suspect it has a cracked heat exchanger, as this could make your entire household ill. Call an HVAC professional immediately if you think your furnace has a cracked heat exchanger that should be repaired.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger could cause your furnace to shut off.
  • Strange Smells: If the air leaving your furnace has a strong chemical odor, it might be a sign gasses are seeping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you recognize health problems: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm should go off or family members may experience signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If the alarm goes off or you feel sick, leave the home as soon as you can and then call for help.
  • Soot: If you spot black sooty collecting on the exterior of your furnace, it’s an indication something could be seriously wrong.

What to Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation Crestview right away so they can take a look at your system and, if required, handle a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

However, the good news is that heat exchangers are regularly included in the warranty. You’ll want to check the warranty paperwork on your furnace, as while the warranty won't always cover the entire cost of repairs, it still may 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 routine furnace maintenance. Furnaces offer the most benefits when they run efficiently. Hiring a trained professional to examine your furnace for worn-out parts, clogged filters and other likely problems can help you avoid 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 ideal 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 pulling air through a clogged filter makes your entire furnace work harder to complete its job. And the harder your furnace has to work, the more wear and tear pieces like the heat exchanger will sustain.