A furnace is often a background player for your home, ensuring you're warm in the cold winter months. It frequently isn't noticed until a malfunction appears.
One root cause could be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to familiarize yourself with the evidence of a cracked heat exchanger and what to do if you are worried 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 circulates through the system. It generally accomplishes this using coils or tubes that heat up the air while functioning 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?
Thanks to its important role, it shouldn't come as a surprise that a cracked heat exchanger can pose a risk. A crack in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to be distributed through your home.
For this reason, never turn on your heating if you believe there's a crack in the heat exchanger, as this could make the whole household sick. Contact an HVAC professional immediately if you are worried your heating has a cracked heat exchanger that needs to be repaired.
Four Signs of a Cracked Heat Exchanger:
- Furnace turns 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 may be an indicator that gas is slipping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm goes off or you recognize health problems: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should go off or household members might 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 unwell, get out of the home immediately and then call for help.
- Soot: If you spot black sooty collecting around 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 suspect your furnace has a cracked heat exchanger, hire a pro well versed in furnace installation right away so they can inspect your system and, if necessary, perform a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are regularly protected by the warranty. You should review the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it can significantly lower 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 regular furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a skilled professional to examine your furnace for old parts, clogs in the air filters and other common 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 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 dragging 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 deterioration components like the heat exchanger will endure.