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

September 20, 2022

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

One root cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to familiarize yourself with the signs of a cracked heat exchanger and what you should 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 inside your furnace to the air that flows through the system. It typically does this through coils or tubes that warm the air while functioning as a barrier to keep gas created in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its central role, it isn't surprising that a cracked heat exchanger can pose a risk. A damaged heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow through your home.

For this reason, don't ever use your heater if you suspect you're dealing with a cracked heat exchanger, as letting it run could make your entire household sick. Reach out to an HVAC professional immediately if you think your furnace has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger can cause your furnace to switch off.
  • Odd Smells: If the air escaping your furnace has a powerful chemical smell, it may be an indicator that gas is leaking through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm goes off or you notice health problems: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm could go off or family members could start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel sick, exit the home immediately and then call for help.
  • Soot: If you spot black sooty buildup around the exterior of your furnace, it’s an indication something could be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, call a professional well versed in furnace installation Milledgeville and Middle Georgia as soon as possible so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

However, the good news is that heat exchangers are generally included in the warranty. You should check the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it could significantly shrink 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 with routine furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Calling a skilled professional to examine your furnace for worn-out parts, clogs in the air filters and other common 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 recommended 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 the entire furnace work harder to complete its job. And the harder your furnace needs to run, the more deterioration parts like the heat exchanger will sustain.