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

September 20, 2022

A furnace is usually a background player at home, helping keep you warm across the cold winter months. It regularly won't be noticed until something breaks down.

One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the signs of a cracked heat exchanger and what to do if you believe that may be 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 moves inside the air ducts. It usually does this with coils or tubes that heat the air while functioning as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Because of its important role, it shouldn't come as a surprise that a cracked heat exchanger can be very dangerous. Cracks in the heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to circulate through your home.

For obvious reasons, do NOT run your heating if you suspect it has a cracked heat exchanger, as letting it run could make the whole family ill. Contact an HVAC professional right away if you believe your heater has a cracked heat exchanger that should be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger could cause your furnace to switch off.
  • Strange Smells: If the air leaving 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 major warning sign.
  • Carbon monoxide alarm initiates or you notice symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm could go off or household members may struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unusually tired, get out of the home as soon as you can and then call for help.
  • Soot: If you spot black sooty collecting on the exterior of your furnace, it’s more evidence something could be seriously wrong.

What You Can Do if the Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, hire a pro experienced in furnace installation Alice right away so they can take a look at your system and, if required, start a furnace heat exchanger replacement. Costs often vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are often protected by the warranty. You should check the warranty paperwork on your furnace, as while the warranty won't always 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 minimize the risk of problems in your furnace overall is via routine furnace maintenance. Furnaces work the best when they operate 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 helpful to review your furnace filters every few months – it’s ideal some filters be changed 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 longer to accomplish its job. And the harder your furnace needs to run, the more deterioration components like the heat exchanger will experience.