A furnace is usually a background player at home, ensuring you're warm during the cold winter months. It often isn't noticed until something breaks down.
One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to familiarize yourself with the signs of a cracked heat exchanger and what to do if you believe that is 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 through the ventilation. It usually handles this with coils or tubes that warm the air while functioning as a barrier to keep gas created in the combustion chamber, called flue gasses, from escaping out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its central role, it’s no surprise that a damaged heat exchanger can pose a risk. A crack in the heat exchanger can permit dangerous gasses – including carbon monoxide, which can be lethal – to flow through your home.
For this reason, never turn on your furnace if you suspect it has a cracked heat exchanger, as this could make the whole family ill. Contact an HVAC professional right away if you are worried your furnace has a cracked heat exchanger that needs repair.
Four Signs of a Cracked Heat Exchanger:
- Furnace switches off: Cracks in the heat exchanger could cause your furnace to shut off.
- Unusual Smells: If the air escaping your furnace has an intense chemical odor, it could be evidence gas is slipping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm is triggered or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm should go off or family members might experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel sick, leave the home as soon as you can and then call for help.
- Soot: If you spot black sooty accumulating on the exterior of your furnace, it’s an indication something may be seriously wrong.
What to Do if the Furnace Heat Exchanger is Cracked
If you believe your furnace has a cracked heat exchanger, contact a pro experienced in furnace installation right away so they can take a look at your system and, if necessary, perform a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates often hover around $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are regularly included in the warranty. You should confirm the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it can significantly lower your bill.
How to Avoid 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 offer the most benefits when they work efficiently. Contacting a skilled professional to examine your furnace for worn-out parts, clogs in the air filters and other common problems can help you avoid 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 are not part of the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work harder to complete its job. And the harder your furnace has to work, the more strain parts like the heat exchanger will experience.