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

September 20, 2022

A furnace is usually a background player for your home, ensuring you're warm across the cold winter months. It frequently isn't noticed until a malfunction appears.

One source might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to know the evidence of a cracked heat exchanger and what you should do if you believe that might be 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 moves throughout the ventilation. It usually does this through coils or tubes that heat the air while functioning as a barrier to keep gas created in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its important role, it’s no surprise that a damaged heat exchanger can be hazardous. A crack in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to circulate throughout your home.

For that reason, never use your heater if you believe you're dealing with a cracked heat exchanger, as letting it run could make your entire household sick. Contact an HVAC professional right away if you think your heater has a cracked heat exchanger that should be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger may cause your furnace to turn off.
  • Unusual Smells: If the air leaving your furnace has a strong chemical odor, it might be a sign gasses are slipping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm initiates or you notice poisoning symptoms: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm should go off or family members could start experiencing 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 as soon as you can and then call for help.
  • Soot: If you notice black sooty collecting around the exterior of your furnace, it’s more evidence something might be seriously wrong.

What You Can 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 Buellton right away so they can inspect your system and, if needed, start a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are generally protected by the warranty. You should review the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it can significantly reduce 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 regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Hiring a skilled professional to check your furnace for broken-down parts, clogs in the air filters and other potential problems can keep you from 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 drawing air through a clogged filter makes the entire furnace work more vigorously to do its job. And the harder your furnace has to work, the more deterioration parts like the heat exchanger will endure.