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

September 20, 2022

A furnace is almost always a background player in your home, ensuring you're warm in the cold winter months. It often isn't 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 evidence of a cracked heat exchanger and what you should do if you are worried that might 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 inside the system. It usually accomplishes this through coils or tubes that warm the air while serving as a barrier to keep gas created in the combustion chamber, called flue gasses, from leaking 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 hazardous. A damaged heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to circulate throughout your home.

For that reason, don't ever use your heater if you suspect there's a crack in the heat exchanger, as doing so could make the entire family ill. Call an HVAC professional immediately if you believe your heating has a cracked heat exchanger that needs repair.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger may cause your furnace to turn off.
  • Strange Smells: If the air leaving your furnace has a strong chemical smell, it might be evidence gas is slipping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm is triggered or you recognize health problems: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm should go off or household members could experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel sick, get out of the home as soon as you can and then call for help.
  • Soot: If you see black sooty buildup near the exterior of your furnace, it’s an indication something could be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, hire a pro experienced in furnace installation Odessa as soon as possible so they can take a look at your system and, if necessary, perform a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates can roughly suggest $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, since while the warranty won't always cover the entire cost of repairs, it can significantly lower your bill.

How to Avoid a Cracked Heat Exchanger in Your Home

One of the easiest ways to avoid problems in your furnace overall is with consistent furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Hiring a trained professional to check your furnace for old parts, clogs in the air filters and other potential problems can help you avoid getting a big bill later on.

It’s also beneficial to inspect your furnace filters every few months – it’s encouraged 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 pulling air through a clogged filter makes the entire furnace work longer to complete its job. And the harder your furnace needs to run, the more strain parts like the heat exchanger will sustain.