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

September 20, 2022

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

One source might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the symptoms of a cracked heat exchanger and what to do if you suspect 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 air ducts. It usually accomplishes this via coils or tubes that heat up the air while acting as a barrier to keep gas formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its key role, it’s no surprise that a broken heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to flow through your home.

For this reason, never use your heating if you believe you're dealing with a cracked heat exchanger, as this could make your entire family sick. Call an HVAC professional right away if you are worried your furnace has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger could cause your furnace to switch off.
  • Unusual Smells: If the air escaping your furnace has an intense chemical scent, it may be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you recognize poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm may go off or household members could start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel unusually tired, exit the home as soon as you can and then call for help.
  • Soot: If you find black sooty buildup near the exterior of your furnace, it’s another sign something could be seriously wrong.

What You Can Do if the Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a professional with extensive experience in furnace installation Port St. Lucie right away so they can inspect your system and, if required, handle a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are regularly included in the warranty. You’ll want to check the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it still may significantly lower your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to avoid problems in your furnace overall is with regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Hiring a certified professional to check your furnace for worn-out parts, dirty filters and other likely 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 swapped out 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 drawing air through a clogged filter makes the entire furnace work more vigorously to accomplish its job. And the harder your furnace works, the more wear and tear components like the heat exchanger will endure.