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

September 20, 2022

A furnace is often a background player for your home, ensuring you're warm across the cold winter months. It regularly won't be noticed until something goes wrong.

One source might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to know the signs of a cracked heat exchanger and what you can do if you believe that might be 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 circulates through the system. It typically accomplishes this with coils or tubes that warm the air while functioning as a barrier to keep the gasses produced in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it isn't surprising that a cracked heat exchanger can be very dangerous. A crack in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to circulate throughout your home.

For this reason, do NOT turn on your heater if you believe you're dealing with a cracked heat exchanger, as letting it run could make the entire family sick. Contact an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace switches off: A crack in your heat exchanger may cause your furnace to shut off.
  • Strange Smells: If the air coming out of your furnace has an intense chemical smell, it might be evidence gasses are slipping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you recognize symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm could go off or household members could struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unusually tired, get out of the home as soon as you can and then call for help.
  • Soot: If you see black sooty accumulating around the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Can Do if the Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, hire a pro with extensive experience in furnace installation New Castle as soon as possible so they can take a look at your system and, if required, perform a furnace heat exchanger replacement. Costs often vary depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are generally protected by the warranty. You’ll want to confirm the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it could 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 via routine furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Contacting a certified professional to inspect your furnace for broken-down parts, clogged filters and other common 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 encouraged some filters be swapped out 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 harder to complete its job. And the harder your furnace needs to run, the more strain components like the heat exchanger will endure.