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

September 20, 2022

A furnace is almost always a background player for your home, ensuring you're warm across the cold winter months. It regularly won't be noticed until something goes wrong.

One root cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s worthwhile to learn the signs 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 transition heat from the combustion chamber in your furnace to the air that flows through the system. It generally accomplishes this through coils or tubes that heat up the air while serving 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?

Because of its important role, it’s no surprise that a damaged heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed through your home.

For that reason, never turn on your heating if you suspect it has a cracked heat exchanger, as letting it run could make the whole household sick. Reach out to an HVAC professional immediately if you think your heating has a cracked heat exchanger that needs to be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger can cause your furnace to turn off.
  • Strange Smells: If the air leaving your furnace has a powerful chemical smell, it might be an indicator that gas is seeping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm could go off or family members might start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel unusually tired, get out of the home as soon as you can and then call for help.
  • Soot: If you find black sooty buildup around the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation Excelsior Springs right away so they can inspect your system and, if necessary, perform a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.

Fortunately, the good news is that heat exchangers are regularly included in the warranty. It's a good idea to check the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it could significantly lower your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the most convenient ways to prevent a problem in your furnace overall is through routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Hiring a skilled professional to check your furnace for worn-out parts, dirty filters and other likely problems can help you avoid getting a big bill later on.

It’s also beneficial to take a look at your furnace filters every few months – it’s recommended some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work harder to accomplish its job. And the harder your furnace has to work, the more strain components like the heat exchanger will endure.