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

September 20, 2022

A furnace is almost always a background player in your home, keeping you warm across the cold winter months. It frequently doesn’t get noticed until something breaks down.

One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to familiarize yourself with the evidence of a cracked heat exchanger and what you can do if you are worried that is the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps move heat from the combustion chamber in your furnace to the air that flows throughout the ventilation. It generally accomplishes this via coils or tubes that heat up the air while acting as a barrier to keep the gasses formed 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 shouldn't come as a surprise that a damaged heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to circulate across your home.

For obvious reasons, do NOT run your heater if you believe it has a cracked heat exchanger, as this could make the whole household sick. Reach out to an HVAC professional right away if you believe your heating has a cracked heat exchanger that should be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger could 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 slipping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you recognize poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm may go off or household members could start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If the alarm goes off or you feel unusually tired, get out of the home right away and then call for help.
  • Soot: If you spot black sooty accumulating on the exterior of your furnace, it’s another sign something may be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation Rock Hill as soon as possible so they can inspect your system and, if needed, start a furnace heat exchanger replacement. Costs often differ 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 included in the warranty. You should review the warranty paperwork on your furnace, as 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 easiest ways to prevent a problem in your furnace overall is with regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Hiring a certified professional to inspect your furnace for worn-out parts, dirty filters and other likely problems can keep you from getting a big bill later on.

It’s also beneficial to take a look at your furnace filters every few months – it’s recommended some filters be changed every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to 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 has to work, the more deterioration components like the heat exchanger will experience.