A furnace is usually a background player at home, ensuring you're warm across the cold winter months. It regularly doesn’t get noticed until something breaks down.
One cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to learn the evidence of a cracked heat exchanger and what you can 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 moves through the system. It generally accomplishes this through coils or tubes that heat up the air while serving as a barrier to keep gas created in the combustion chamber, called flue gasses, from getting out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its important role, it isn't surprising that a cracked heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to circulate across your home.
For that reason, don't ever run your heating if you believe you're dealing with a cracked heat exchanger, as this could make the entire household ill. Contact an HVAC professional as soon as possible if you think your furnace has a cracked heat exchanger that should be repaired.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace shuts off: Cracks in the heat exchanger could cause your furnace to turn off.
- Unusual Smells: If the air escaping your furnace has a powerful chemical smell, it might be a sign gas is seeping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm initiates or you notice symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm should go off or family members may start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel unusually tired, get out of the home right away and then call for help.
- Soot: If you spot black sooty accumulating near the exterior of your furnace, it’s another sign something could be seriously wrong.
What You Should Do if a Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, call a professional experienced in furnace installation as soon as possible so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are regularly covered by the warranty. You should review the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it could significantly lower your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the best ways to avoid problems in your furnace overall is with routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Contacting a certified professional to check your furnace for worn-out parts, dirty filters and other common problems can help you avoid getting a big bill later on.
It’s also helpful to take a look at 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 aren't a part of the heat exchanger itself, the strain of dragging air through a clogged filter makes the entire furnace work harder to accomplish its job. And the harder your furnace needs to run, the more wear and tear components like the heat exchanger will sustain.