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

September 20, 2022

A furnace is almost always a background player at home, ensuring you're warm during the cold winter months. It frequently isn't noticed until a malfunction appears.

One cause may be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to familiarize yourself with the evidence of a cracked heat exchanger and what you should 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 of your furnace to the air that flows inside the system. It generally handles this via coils or tubes that warm the air while acting 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 central role, it isn't surprising that a cracked heat exchanger can be hazardous. Cracks in the heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to flow across your home.

For this reason, do NOT use your heating if you suspect there's a crack in the heat exchanger, as this could make your entire household ill. Call an HVAC professional right away if you are worried your heater has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: Cracks in the heat exchanger can cause your furnace to turn off.
  • Odd Smells: If the air coming out of your furnace has an intense chemical smell, it could be evidence gasses are seeping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm goes off or you feel health problems: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members could struggle with signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unwell, get out of the home immediately and then call for help.
  • Soot: If you find black sooty accumulating near the exterior of your furnace, it’s an indication something may be seriously wrong.

What to 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 Bend right away so they can inspect your system and, if required, start a furnace heat exchanger replacement. Costs should 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 included in the warranty. You should check the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it still may significantly shrink your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the best ways to avoid problems in your furnace overall is through regular furnace maintenance. Furnaces work the best when they operate efficiently. Calling a trained professional to check your furnace for old parts, clogged filters and other likely problems can keep you from getting a big bill later on.

It’s also helpful to inspect 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 are not part of the heat exchanger itself, the strain of pulling air through a clogged filter makes your entire furnace work harder to complete its job. And the harder your furnace works, the more wear and tear parts like the heat exchanger will endure.