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

September 20, 2022

A furnace is often a background player for your home, keeping you warm in the cold winter months. It frequently isn't noticed until something goes wrong.

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

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps transition heat from the combustion chamber of your furnace to the air that circulates inside the ventilation. It typically does this via coils or tubes that heat up the air while acting as a barrier to keep gas created in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its important role, it’s no surprise that a damaged heat exchanger can be very dangerous. A crack in the heat exchanger can enable dangerous gasses – including carbon monoxide, which can be lethal – to be distributed through your home.

For obvious reasons, don't ever use your furnace if you think there's a crack in the heat exchanger, as this could make the entire household sick. Reach out to an HVAC professional as soon as possible if you are worried your heating has a cracked heat exchanger that needs repair.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace shuts off: Cracks in the heat exchanger can cause your furnace to shut off.
  • Unusual Smells: If the air leaving your furnace has a powerful chemical smell, it could be evidence gas is seeping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should go off or household members could start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unusually tired, get out of the home immediately and then call for help.
  • Soot: If you find black sooty collecting around the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Should Do if a Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, hire a professional experienced in furnace installation Longview as soon as possible so they can inspect your system and, if needed, handle a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are regularly covered by the warranty. It's a good idea to confirm the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it could significantly reduce your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to prevent a problem in your furnace overall is via regular furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Calling a skilled professional to examine your furnace for old parts, dirty filters and other likely 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 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 pulling air through a clogged filter makes the entire furnace work more vigorously to do its job. And the harder your furnace works, the more wear and tear pieces like the heat exchanger will sustain.