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

September 20, 2022

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

One cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to know the evidence of a cracked heat exchanger and what you can do if you suspect that is the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger transfers heat from the combustion chamber inside your furnace to the air that moves through the ventilation. It usually accomplishes this using coils or tubes that heat the air while serving 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?

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

For that reason, don't ever run your heating if you think it has a cracked heat exchanger, as letting it run could make your entire family ill. Contact an HVAC professional as soon as possible if you believe your heater has a cracked heat exchanger that needs to be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: Cracks in the heat exchanger can cause your furnace to switch off.
  • Odd Smells: If the air leaving your furnace has an intense chemical scent, it may be an indicator that gasses are leaking through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you recognize health problems: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm could go off or family members might start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel sick, leave the home right away and then call for help.
  • Soot: If you notice black sooty collecting on the exterior of your furnace, it’s an indication something might be seriously wrong.

What to Do if a Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Columbia right away so they can inspect your system and, if needed, handle a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are often protected by the warranty. It's a good idea to review the warranty paperwork on your furnace, because 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 most convenient ways to avoid problems in your furnace overall is through consistent furnace maintenance. Furnaces offer the most benefits when they run efficiently. Calling a certified professional to inspect your furnace for old parts, clogged filters and other likely problems can keep you from getting a big bill later on.

It’s also a good idea to review 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 aren't connected to the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work more vigorously to accomplish its job. And the harder your furnace works, the more strain parts like the heat exchanger will sustain.