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

September 20, 2022

A furnace is almost always a background player for your home, helping keep you warm in the cold winter months. It frequently won't be noticed until a malfunction appears.

One cause could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to know the symptoms of a cracked heat exchanger and what to do if you suspect 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 circulates inside the system. It generally accomplishes this using coils or tubes that warm the air while serving as a barrier to keep gas formed in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

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

For obvious reasons, don't ever run your furnace if you think it has a cracked heat exchanger, as letting it run could make the whole family sick. Reach out to an HVAC professional immediately 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 crack in your heat exchanger can cause your furnace to shut off.
  • Unusual Smells: If the air escaping your furnace has a strong chemical odor, it might be an indicator that gasses are leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you notice poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm may go off or household members might struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel unwell, leave the home right away and then call for help.
  • Soot: If you spot black sooty accumulating around the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, contact a pro with extensive experience in furnace installation Laurel as soon as possible so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

However, the good news is that heat exchangers are regularly covered by the warranty. You’ll want to check the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it still may significantly shrink 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 work the best when they run efficiently. Calling a certified professional to inspect your furnace for broken-down parts, clogged filters and other common problems can keep you from getting a big bill later on.

It’s also a good idea 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 aren't a part of the heat exchanger itself, the strain of pulling air through a clogged filter makes the entire furnace work longer to complete its job. And the harder your furnace needs to run, the more wear and tear parts like the heat exchanger will endure.