A furnace is often a background player in your home, ensuring you're warm in the cold winter months. It regularly isn't noticed until a malfunction appears.
One source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the evidence of a cracked heat exchanger and what you should do if you are worried that is the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps move heat from the combustion chamber in your furnace to the air that flows throughout the system. It generally handles this via coils or tubes that warm the air while acting 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?
Because of its central role, it’s no surprise that a broken heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to be distributed across your home.
For that reason, don't ever turn on your furnace if you think there's a crack in the heat exchanger, as doing so could make your entire family sick. Contact an HVAC professional right away if you think your heater 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 may cause your furnace to switch off.
- Unusual Smells: If the air coming out of your furnace has an intense chemical odor, it may be a sign gas is leaking through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm initiates or you feel symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm could go off or household members may experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, exit the home immediately and then call for help.
- Soot: If you find black sooty accumulating on the exterior of your furnace, it’s an indication something may 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 professional with extensive experience in furnace installation as soon as possible so they can examine your system and, if needed, perform a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are often covered by the warranty. You should confirm the warranty paperwork on your furnace, because while the warranty might 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 through regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Hiring a skilled professional to check 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 a good idea 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 drawing 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 strain components like the heat exchanger will endure.