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

September 20, 2022

A furnace is almost always a background player in your home, keeping you warm during the cold winter months. It regularly won't be noticed until something breaks down.

One source might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to familiarize yourself with the symptoms 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 transfers heat from the combustion chamber in your furnace to the air that moves through the air ducts. It generally does this with coils or tubes that heat up the air while functioning as a barrier to keep the gasses created in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its key role, it shouldn't come as a surprise that a broken heat exchanger can be very dangerous. A damaged heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to be distributed through your home.

For this reason, never turn on your heater if you think it has a cracked heat exchanger, as letting it run could make the whole family sick. Call an HVAC professional immediately if you believe your furnace has a cracked heat exchanger that needs repair.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace switches off: A crack in your heat exchanger can cause your furnace to turn off.
  • Odd Smells: If the air escaping your furnace has an intense chemical smell, it could be evidence gas is seeping through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you recognize poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm could go off or family 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, leave the home right away and then call for help.
  • Soot: If you see black sooty buildup near the exterior of your furnace, it’s another sign something may be seriously wrong.

What You Should Do if a Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, contact a professional experienced in furnace installation Kearney as soon as possible so they can take a look at your system and, if required, start a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

However, the good news is that heat exchangers are regularly protected by the warranty. It's a good idea to confirm the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it could significantly shrink your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the best ways to minimize the risk of problems in your furnace overall is via regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Contacting a trained professional to check your furnace for broken-down parts, clogs in the air filters and other common problems can keep you from getting a big bill later on.

It’s also beneficial to take a look at your furnace filters every few months – it’s ideal some filters be replaced 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 dragging air through a clogged filter makes the entire furnace work longer to complete its job. And the harder your furnace works, the more strain components like the heat exchanger will endure.