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

September 20, 2022

A furnace is almost always a background player for your home, ensuring you're warm across the cold winter months. It regularly won't be noticed until something breaks down.

One root cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s important to familiarize yourself with the symptoms of a cracked heat exchanger and what you can do if you suspect that is 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 moves inside the system. It usually accomplishes this using coils or tubes that warm the air while serving as a barrier to keep byproducts produced 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 shouldn't come as a surprise that a broken heat exchanger can be very dangerous. A damaged heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to circulate through your home.

For this reason, never use your furnace if you believe it has a cracked heat exchanger, as this could make the whole family ill. Reach out to an HVAC professional immediately if you are worried your heating has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger may cause your furnace to shut off.
  • Strange Smells: If the air escaping your furnace has a strong chemical odor, it might be a sign gasses are leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm is triggered or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should 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 your alarm goes off or you feel unusually tired, exit the home right away and then call for help.
  • Soot: If you see black sooty buildup on the exterior of your furnace, it’s an indication something could be seriously wrong.

What You Should Do if a Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Laguna Niguel right away so they can inspect your system and, if required, handle a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are often protected by the warranty. You should review the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it could significantly lower your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to minimize the risk of problems in your furnace overall is via routine furnace maintenance. Furnaces offer the most benefits when they run efficiently. Contacting a certified professional to examine 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 helpful to review 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 aren't a part of the heat exchanger itself, the strain of pulling 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 components like the heat exchanger will endure.