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

September 20, 2022

A furnace is often a background player for your home, keeping you warm across the cold winter months. It frequently doesn’t get noticed until something goes wrong.

One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the signs of a cracked heat exchanger and what you can do if you believe that is 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 flows inside the air ducts. It generally accomplishes this using coils or tubes that heat the air while functioning as a barrier to keep the gasses produced in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its important role, it shouldn't come as a surprise that a broken heat exchanger can be very dangerous. A crack in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow across your home.

For obvious reasons, never turn on your heating if you suspect 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 believe your heating has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace shuts off: Cracks in the heat exchanger may cause your furnace to turn off.
  • Odd Smells: If the air leaving your furnace has an intense chemical smell, it might be an indicator that gas is leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm is triggered or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm could go off or family members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an 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 find black sooty accumulating on the exterior of your furnace, it’s another sign something could be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked

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

Estimates aside, the good news is that heat exchangers are generally covered by the warranty. It's a good idea to confirm the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it still may significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the most convenient ways to prevent a problem in your furnace overall is through consistent furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Hiring a certified professional to check your furnace for worn-out 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 inspect your furnace filters every few months – it’s encouraged some filters be replaced 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 pulling air through a clogged filter makes your entire furnace work longer to accomplish its job. And the harder your furnace works, the more wear and tear components like the heat exchanger will sustain.