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

September 20, 2022

A furnace is often a background player for your home, ensuring you're warm during the cold winter months. It regularly 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 critical to learn the symptoms of a cracked heat exchanger and what to do if you believe that is 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 throughout the air ducts. It usually accomplishes this with coils or tubes that heat up the air while acting 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?

Because of its central role, it shouldn't come as a surprise that a broken heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.

For that reason, do NOT turn on your heater if you think there's a crack in the heat exchanger, as doing so could make your entire family sick. Reach out to an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger may cause your furnace to switch off.
  • Odd Smells: If the air escaping your furnace has a powerful chemical scent, it could be an indicator that gas is leaking through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm may go off or household members might start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel unusually tired, leave the home right away and then call for help.
  • Soot: If you find black sooty buildup near the exterior of your furnace, it’s an indication something could be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation Lake Worth as soon as possible so they can examine your system and, if needed, perform a furnace heat exchanger replacement. Costs will 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 often covered by the warranty. You’ll want to confirm the warranty paperwork on your furnace, since 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 best ways to prevent a problem in your furnace overall is via consistent furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Calling a skilled professional to examine your furnace for broken-down parts, dirty filters and other common problems can help you avoid 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 dragging air through a clogged filter makes the entire furnace work more vigorously to accomplish its job. And the harder your furnace needs to run, the more wear and tear parts like the heat exchanger will experience.