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

September 20, 2022

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

One cause might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the evidence of a cracked heat exchanger and what you should 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 inside your furnace to the air that flows through the system. It generally accomplishes this using coils or tubes that warm the air while serving as a barrier to keep the gasses created in the combustion chamber, called flue gasses, from leaking out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it isn't surprising that a damaged heat exchanger can be very dangerous. A damaged heat exchanger can enable dangerous gasses – including carbon monoxide, which can be lethal – to circulate through your home.

For that reason, don't ever use your heating if you suspect you're dealing with a cracked heat exchanger, as doing so could make the entire family sick. Contact an HVAC professional as soon as possible if you think your furnace has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger can cause your furnace to turn off.
  • Unusual Smells: If the air leaving your furnace has a strong chemical odor, it might be a sign gas is seeping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a significant warning sign.
  • Carbon monoxide alarm goes off or you notice symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm may go off or household members may start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unusually tired, exit the home right away and then call for help.
  • Soot: If you spot black sooty accumulating near the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked

If you suspect your furnace has a cracked heat exchanger, call a pro well versed in furnace installation Dayton right away so they can take a look at your system and, if needed, perform a furnace heat exchanger replacement. Costs will vary 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 may not cover the entire cost of repairs, it can significantly lower your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the best ways to minimize the risk of problems in your furnace overall is through regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Calling a certified professional to examine your furnace for old parts, clogged filters and other common problems can keep you from getting a big bill later on.

It’s also helpful to inspect your furnace filters every few months – it’s ideal some filters be replaced 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 your entire furnace work more vigorously to accomplish its job. And the harder your furnace needs to run, the more strain pieces like the heat exchanger will experience.