A furnace is usually a background player in your home, ensuring you're warm in the cold winter months. It frequently won't be noticed until something breaks down.
One root cause could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to know the symptoms of a cracked heat exchanger and what you can 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 flows inside the air ducts. It typically accomplishes this using coils or tubes that heat up the air while functioning 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?
Because of its important role, it shouldn't come as a surprise that a damaged heat exchanger can pose a risk. A damaged heat exchanger can permit dangerous gasses – including carbon monoxide, which can be lethal – to flow across your home.
For obvious reasons, don't ever use your furnace if you believe it has a cracked heat exchanger, as this could make the entire household ill. Reach out to an HVAC professional immediately if you think your furnace has a cracked heat exchanger that needs to be repaired.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace switches off: A crack in your heat exchanger could cause your furnace to shut off.
- Odd Smells: If the air coming out of your furnace has a powerful chemical odor, it may be a sign gasses are seeping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm goes off or you notice poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm could go off or household members might struggle with signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel sick, get out of the home immediately and then call for help.
- Soot: If you find black sooty accumulating around the exterior of your furnace, it’s an indication something might be seriously wrong.
What You Should Do if Your Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, contact a pro experienced in furnace installation as soon as possible so they can take a look at your system and, if necessary, start a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.
However, the good news is that heat exchangers are regularly included in the warranty. It's a good idea to check the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it could significantly shrink your bill.
How to Avoid a Cracked Heat Exchanger in Your Home
One of the best ways to minimize the risk of problems in your furnace overall is through routine furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Hiring a certified professional to check your furnace for worn-out parts, dirty filters and other likely problems can keep you from getting a big bill later on.
It’s also beneficial to inspect your furnace filters every few months – it’s encouraged 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 drawing air through a clogged filter makes the entire furnace work harder to complete its job. And the harder your furnace needs to run, the more deterioration parts like the heat exchanger will experience.