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

September 20, 2022

A furnace is usually a background player in your home, ensuring you're warm in the cold winter months. It regularly doesn’t get noticed until something goes wrong.

One cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to learn the signs of a cracked heat exchanger and what you can 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 flows through the air ducts. It typically handles this with coils or tubes that heat the air while functioning as a barrier to keep gas formed in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Thanks to its key role, it’s no surprise that a cracked heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to flow through your home.

For that reason, don't ever run your furnace if you believe you're dealing with a cracked heat exchanger, as this could make the entire family sick. Call an HVAC professional immediately if you think your heater has a cracked heat exchanger that needs to be repaired.

Four Symptoms of a Cracked Heat Exchanger:

  • Furnace turns off: Cracks in the heat exchanger could cause your furnace to shut off.
  • Odd Smells: If the air coming out of your furnace has a powerful chemical smell, it may be evidence gasses are 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 recognize health problems: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm could go off or family members could start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel sick, exit the home as soon as you can and then call for help.
  • Soot: If you find black sooty collecting near the exterior of your furnace, it’s more evidence something might be seriously wrong.

What You Can Do if the Furnace Heat Exchanger is Cracked

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

Fortunately, the good news is that heat exchangers are regularly protected by the warranty. You should review the warranty paperwork on your furnace, as 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 through routine furnace maintenance. Furnaces offer the most benefits when they work efficiently. Contacting a certified professional to examine your furnace for worn-out parts, clogged filters and other likely 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 recommended some filters be changed 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 more vigorously to accomplish its job. And the harder your furnace works, the more strain components like the heat exchanger will endure.