A furnace is usually a background player for your home, helping keep you warm during the cold winter months. It regularly isn't noticed until something breaks down.
One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to know the evidence of a cracked heat exchanger and what you should do if you suspect that might be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger transfers heat from the combustion chamber of your furnace to the air that circulates inside the air ducts. It typically accomplishes this with coils or tubes that heat up the air while acting as a barrier to keep byproducts formed 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 broken heat exchanger can be very dangerous. A damaged heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to be distributed across your home.
For obvious reasons, don't ever run your heating if you suspect you're dealing with a cracked heat exchanger, as letting it run could make the whole family sick. Contact an HVAC professional as soon as possible if you are worried your heating has a cracked heat exchanger that needs repair.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace shuts off: A crack in your heat exchanger could cause your furnace to turn off.
- Strange Smells: If the air leaving your furnace has a strong chemical smell, it could be a sign gasses are slipping through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm goes off or you recognize poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm could go off or household members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, leave the home right away and then call for help.
- Soot: If you see black sooty buildup near the exterior of your furnace, it’s another sign something may be seriously wrong.
What You Can Do if the Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation right away so they can examine your system and, if necessary, perform a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.
Estimates aside, the good news is that heat exchangers are often covered by the warranty. You’ll want to review the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it could significantly reduce your bill.
How to Avoid a Cracked Heat Exchanger in Your Home
One of the most convenient ways to minimize the risk of problems in your furnace overall is via consistent furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Contacting a certified professional to check your furnace for broken-down 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 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 your entire furnace work harder to accomplish its job. And the harder your furnace needs to run, the more deterioration pieces like the heat exchanger will experience.
