A furnace is often a background player for your home, keeping you warm across the cold winter months. It regularly won't be noticed until something goes wrong.
One source might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the evidence of a cracked heat exchanger and what you should do if you are worried that may be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger transfers heat from the combustion chamber inside your furnace to the air that flows inside the air ducts. It usually accomplishes this through coils or tubes that heat the air while serving as a barrier to keep the gasses created in the combustion chamber, called flue gasses, from leaking out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its important role, it shouldn't come as a surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.
For this reason, don't ever turn on your heating if you think there's a crack in the heat exchanger, as letting it run could make the whole family ill. Call an HVAC professional immediately if you are worried your furnace has a cracked heat exchanger that needs to be repaired.
Four Signs of a Cracked Heat Exchanger:
- Furnace shuts off: A cracked heat exchanger can cause your furnace to turn off.
- Unusual Smells: If the air coming out of your furnace has an intense chemical scent, it may be a sign gasses are leaking through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm should go off or household members might struggle with signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel sick, get out of the home right away and then call for help.
- Soot: If you find black sooty accumulating on the exterior of your furnace, it’s an indication something could be seriously wrong.
What You Can Do if Your Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, contact a professional with extensive experience in furnace installation right away so they can inspect your system and, if required, start a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are generally protected by the warranty. You’ll want to check the warranty paperwork on your furnace, as while the warranty won't always 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 easiest ways to avoid problems in your furnace overall is via consistent furnace maintenance. Furnaces work the best when they run efficiently. Calling 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 beneficial to review your furnace filters every few months – it’s ideal some filters be swapped out 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 pulling air through a clogged filter makes the entire furnace work more vigorously to complete its job. And the harder your furnace needs to run, the more strain parts like the heat exchanger will experience.
