Cracked Heat Exchanger: What That 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 frequently isn't noticed until something goes wrong.

One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to learn the evidence of a cracked heat exchanger and what you can 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 ventilation. It usually accomplishes this via coils or tubes that warm the air while functioning as a barrier to keep the gasses formed in the combustion chamber, called flue gasses, from getting 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 be very dangerous. Cracks in the heat exchanger can enable dangerous gasses – including carbon monoxide, which can be lethal – to circulate through your home.

For that reason, never turn on your furnace if you believe you're dealing with a cracked heat exchanger, as doing so could make the whole household ill. Reach out to an HVAC professional as soon as possible if you think your furnace 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 turn off.
  • Strange Smells: If the air leaving your furnace has a strong chemical scent, it may be evidence gas is seeping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should go off or household members may start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel sick, leave the home right away and then call for help.
  • Soot: If you notice black sooty accumulating on the exterior of your furnace, it’s another sign something could be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a professional with extensive experience in furnace installation Wyandotte right away so they can examine your system and, if necessary, perform a furnace heat exchanger replacement. Costs often vary 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 regularly included in the warranty. You should confirm 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 Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to prevent a problem in your furnace overall is through consistent furnace maintenance. Furnaces work the best when they operate efficiently. Hiring a trained professional to examine your furnace for broken-down parts, dirty filters and other potential problems can keep you from getting a big bill later on.

It’s also helpful 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 are not part of the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work longer to accomplish its job. And the harder your furnace has to work, the more strain parts like the heat exchanger will experience.