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

September 20, 2022

A furnace is often a background player in your home, keeping you warm in the cold winter months. It often won't be noticed until a malfunction appears.

One root cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to learn the symptoms of a cracked heat exchanger and what you can do if you believe that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps move heat from the combustion chamber of your furnace to the air that moves through the system. It generally handles this through coils or tubes that heat the air while serving as a barrier to keep byproducts created in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it’s no surprise that a broken heat exchanger can pose a risk. Cracks in the heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to be distributed through your home.

For this reason, don't ever use your furnace if you think there's a crack in the heat exchanger, as this could make the entire household ill. Call an HVAC professional right away if you think your heater has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace shuts off: A crack in your heat exchanger could cause your furnace to switch off.
  • Strange Smells: If the air coming out of your furnace has a strong chemical odor, it might be an indicator that gas is leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you recognize symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm may go off or household members may 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 immediately and then call for help.
  • Soot: If you find black sooty buildup on the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, contact a professional experienced in furnace installation Ellsworth as soon as possible so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs often 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 generally covered by the warranty. You should review the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it can significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the most convenient ways to minimize the risk of problems in your furnace overall is with routine furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Calling a certified professional to inspect your furnace for broken-down parts, dirty filters and other common 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 changed 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 dragging air through a clogged filter makes the entire furnace work more vigorously to complete its job. And the harder your furnace works, the more strain pieces like the heat exchanger will sustain.