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

September 20, 2022

A furnace is usually a background player for your home, ensuring you're warm in the cold winter months. It regularly doesn’t get 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 worthwhile to know the evidence of a cracked heat exchanger and what to do if you are worried that may be the problem.

What Is a Heat Exchanger in a Furnace?

A heat exchanger helps move heat from the combustion chamber in your furnace to the air that flows throughout the air ducts. It typically accomplishes this via coils or tubes that heat up the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it shouldn't come as a surprise that a broken heat exchanger can be hazardous. Cracks in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed through your home.

For that reason, don't ever run your heating if you think you're dealing with a cracked heat exchanger, as doing so could make the entire household sick. Call an HVAC professional immediately if you believe your furnace has a cracked heat exchanger that should be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A cracked heat exchanger may cause your furnace to switch off.
  • Unusual Smells: If the air escaping your furnace has an intense chemical odor, it could be a sign gasses are slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm initiates or you feel health problems: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm should go off or household members may start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unwell, exit the home immediately and then call for help.
  • Soot: If you spot black sooty collecting on the exterior of your furnace, it’s another sign something could be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

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

Fortunately, the good news is that heat exchangers are generally covered by the warranty. It's a good idea to check the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it could significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the most convenient ways to minimize the risk of problems in your furnace overall is via routine furnace maintenance. Furnaces offer the most benefits when they work efficiently. Hiring a certified professional to examine your furnace for old parts, clogged filters and other potential problems can help you avoid 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 are not part of the heat exchanger itself, the strain of pulling air through a clogged filter makes your entire furnace work longer to do its job. And the harder your furnace works, the more strain pieces like the heat exchanger will experience.