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

September 20, 2022

A furnace is often a background player in your home, keeping you warm in the cold winter months. It regularly isn't noticed until a malfunction appears.

One cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to familiarize yourself with the signs of a cracked heat exchanger and what to 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 inside your furnace to the air that circulates inside the ventilation. It usually handles this through coils or tubes that warm the air while functioning 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 central role, it shouldn't come as a surprise that a cracked heat exchanger can be very dangerous. A crack in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.

For that reason, never turn on your heating if you think it has a cracked heat exchanger, as doing so could make the whole family sick. Call an HVAC professional immediately if you believe your heating has a cracked heat exchanger that needs repair.

Four Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger can cause your furnace to switch off.
  • Strange Smells: If the air escaping your furnace has a strong chemical smell, it may be a sign gas is seeping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a common warning sign.
  • Carbon monoxide alarm goes off or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm should go off or family members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If the alarm goes off or you feel unusually tired, leave the home as soon as you can and then call for help.
  • Soot: If you find black sooty accumulating near the exterior of your furnace, it’s more evidence something might be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked

If you believe your furnace has a cracked heat exchanger, call a pro well versed in furnace installation Tucson as soon as possible so they can take a look at your system and, if necessary, start a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.

However, the good news is that heat exchangers are regularly covered by the warranty. You should check the warranty paperwork on your furnace, since while the warranty might 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 with consistent furnace maintenance. Furnaces offer the most benefits when they work efficiently. Contacting a certified professional to inspect your furnace for broken-down parts, clogs in the air filters and other potential problems can help you avoid getting a big bill later on.

It’s also a good idea 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 connected to the heat exchanger itself, the strain of pulling air through a clogged filter makes the entire furnace work more vigorously to complete its job. And the harder your furnace works, the more deterioration parts like the heat exchanger will experience.