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

September 20, 2022

A furnace is usually a background player in your home, helping keep you warm across the cold winter months. It often won't be noticed until something goes wrong.

One cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s important to learn the signs of a cracked heat exchanger and what you should 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 in your furnace to the air that circulates through the system. It usually accomplishes this with coils or tubes that heat the air while serving 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?

Given its central role, it’s no surprise that a broken heat exchanger can be hazardous. A damaged heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to flow across your home.

For obvious reasons, do NOT use your furnace if you suspect it has a cracked heat exchanger, as letting it run could make your entire family sick. Reach out to an HVAC professional immediately if you think your heating has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger can cause your furnace to switch off.
  • Strange Smells: If the air leaving your furnace has an intense chemical odor, it could be a sign gasses are seeping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm may go off or family members may start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, get out of the home right away and then call for help.
  • Soot: If you see black sooty buildup around the exterior of your furnace, it’s more evidence something could be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, call a pro well versed in furnace installation Kutztown right away so they can take a look at your system and, if required, perform a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are regularly covered by the warranty. You’ll want to confirm the warranty paperwork on your furnace, because 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 with consistent furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Hiring a skilled professional to examine 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 beneficial to review your furnace filters every few months – it’s ideal some filters be swapped out 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 dragging air through a clogged filter makes your entire furnace work more vigorously to do its job. And the harder your furnace works, the more deterioration components like the heat exchanger will sustain.