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

September 20, 2022

A furnace is usually a background player at home, ensuring you're warm during the cold winter months. It frequently doesn’t get noticed until something goes wrong.

One cause may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to learn the symptoms of a cracked heat exchanger and what you should do if you believe that is 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 circulates through the system. It usually handles this with coils or tubes that heat up the air while acting as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from escaping out into your home.

Is a Cracked Heat Exchanger Dangerous?

Given its central role, it isn't surprising that a cracked heat exchanger can be very dangerous. Cracks in the heat exchanger can permit dangerous gasses – including carbon monoxide, which can be lethal – to flow throughout your home.

For this reason, never use your heater if you suspect there's a crack in the heat exchanger, as doing so could make the whole household ill. Call an HVAC professional as soon as possible if you believe your heater has a cracked heat exchanger that needs to be repaired.

Four Signs of a Cracked Heat Exchanger:

  • Furnace switches off: A cracked heat exchanger can cause your furnace to turn off.
  • Unusual Smells: If the air escaping your furnace has a strong chemical scent, it may be a sign gas is seeping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a major warning sign.
  • Carbon monoxide alarm goes off or you feel health problems: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm should go off or family members could start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel sick, exit the home as soon as you can and then call for help.
  • Soot: If you see black sooty collecting on the exterior of your furnace, it’s more evidence something could be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked

If you worry your furnace has a cracked heat exchanger, call a pro well versed in furnace installation Central Point right away so they can inspect your system and, if necessary, handle a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.

Estimates aside, the good news is that heat exchangers are generally protected by the warranty. You’ll want to confirm the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it can significantly reduce your bill.

How to Prevent a Cracked Heat Exchanger in Your Home

One of the easiest ways to prevent a problem in your furnace overall is via regular furnace maintenance. Furnaces offer the most benefits when they work efficiently. Calling a trained professional to check your furnace for old parts, dirty filters and other likely problems can keep you from getting a big bill later on.

It’s also helpful to review 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 pulling air through a clogged filter makes the entire furnace work more vigorously to accomplish its job. And the harder your furnace works, the more deterioration components like the heat exchanger will sustain.