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

September 20, 2022

A furnace is almost always a background player at home, ensuring you're warm in the cold winter months. It regularly won't be noticed until something breaks down.

One cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s important to familiarize yourself with the signs of a cracked heat exchanger and what you should do if you are worried that is 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 circulates through the ventilation. It generally accomplishes this through coils or tubes that heat the air while acting as a barrier to keep gas formed in the combustion chamber, called flue gasses, from getting out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its key role, it’s no surprise that a broken heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to circulate throughout your home.

For obvious reasons, never run your heater if you suspect you're dealing with a cracked heat exchanger, as letting it run could make the whole family ill. Contact an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that needs to be repaired.

Four Warning Signs of a Cracked Heat Exchanger:

  • Furnace turns off: A crack in your heat exchanger may cause your furnace to shut off.
  • Strange Smells: If the air escaping your furnace has a strong chemical odor, it may be an indicator that gasses are slipping through cracks in your heat exchanger. These gasses, which may 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 in your home, your carbon monoxide alarm should go off or family members may start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unusually tired, exit the home right away and then call for help.
  • Soot: If you see black sooty buildup on the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, contact a professional well versed in furnace installation Carpentersville as soon as possible so they can take a look at your system and, if needed, start a furnace heat exchanger replacement. Costs often 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 protected by the warranty. It's a good idea to review the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it still may significantly shrink 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 with routine furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Hiring a certified professional to check your furnace for worn-out parts, dirty filters and other likely 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 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 dragging air through a clogged filter makes the entire furnace work harder to complete its job. And the harder your furnace has to work, the more strain pieces like the heat exchanger will experience.