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

September 20, 2022

A furnace is usually a background player for your home, keeping you warm in the cold winter months. It frequently doesn’t get noticed until a malfunction appears.

One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to familiarize yourself with the signs of a cracked heat exchanger and what you should do if you are worried that is the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps transition heat from the combustion chamber inside your furnace to the air that flows through the system. It generally does this via coils or tubes that warm 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?

Thanks to its important role, it isn't surprising that a damaged heat exchanger can pose a risk. Cracks in the heat exchanger can allow dangerous gasses – like carbon monoxide, which can be lethal – to circulate across your home.

For obvious reasons, don't ever turn on your heater if you think you're dealing with a cracked heat exchanger, as doing so could make the whole household ill. Reach out to an HVAC professional as soon as possible if you are worried your furnace has a cracked heat exchanger that needs repair.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace shuts 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 powerful chemical smell, it might be evidence gas is leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you recognize health problems: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm could go off or family members could start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel sick, leave the home right away and then call for help.
  • Soot: If you see black sooty accumulating around the exterior of your furnace, it’s another sign something may be seriously wrong.

What You Can Do if the Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, call a professional experienced in furnace installation Manassas right away so they can inspect your system and, if required, perform a furnace heat exchanger replacement. Costs often vary 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. 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 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 with regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Contacting a trained professional to examine your furnace for old parts, clogged filters and other potential problems can keep you from getting a big bill later on.

It’s also helpful to inspect 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 drawing 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 wear and tear pieces like the heat exchanger will endure.