A furnace is often a background player in your home, keeping you warm across the cold winter months. It regularly won't be noticed until a malfunction appears.
One source might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to familiarize yourself with the symptoms of a cracked heat exchanger and what you can do if you believe that may be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps transition heat from the combustion chamber in your furnace to the air that flows inside the system. It generally does this via coils or tubes that warm the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from getting out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its key role, it’s no surprise that a cracked heat exchanger can be very dangerous. A damaged heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.
For that reason, don't ever run your heater if you suspect it has a cracked heat exchanger, as doing so could make the whole household sick. Contact an HVAC professional right away if you believe your heating has a cracked heat exchanger that needs repair.
Four Symptoms 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 leaving your furnace has an intense chemical scent, it might be a sign gasses are leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm goes off or you feel health problems: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm should go off or household members may struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unwell, leave the home immediately and then call for help.
- Soot: If you see black sooty buildup near the exterior of your furnace, it’s more evidence something could be seriously wrong.
What You Can Do if Your Furnace Heat Exchanger is Cracked
If you believe your furnace has a cracked heat exchanger, hire a pro with extensive experience in furnace installation right away so they can examine your system and, if needed, perform a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
However, 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 can significantly shrink your bill.
How to Prevent 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 provide the best possible return on investment when they work efficiently. Contacting a certified professional to inspect your furnace for old parts, clogs in the air filters and other common problems can help you avoid getting a big bill later on.
It’s also beneficial to inspect your furnace filters every few months – it’s recommended 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 more vigorously to accomplish its job. And the harder your furnace needs to run, the more strain components like the heat exchanger will sustain.