A furnace is often a background player for your home, helping keep you warm in the cold winter months. It regularly doesn’t get noticed until something goes wrong.
One cause could be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s worthwhile to learn the signs of a cracked heat exchanger and what you can do if you believe that may be 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 through the ventilation. It generally handles this using coils or tubes that warm the air while acting as a barrier to keep the gasses formed 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 isn't surprising that a damaged heat exchanger can be very dangerous. Cracks in the heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.
For that reason, don't ever run your furnace if you suspect there's a crack in the heat exchanger, as letting it run could make your entire family ill. Reach out to an HVAC professional as soon as possible if you believe your heating has a cracked heat exchanger that needs repair.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace turns off: A cracked heat exchanger may cause your furnace to turn off.
- Strange Smells: If the air coming out of your furnace has an intense chemical odor, it may be evidence gas is leaking through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm is triggered or you recognize health problems: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm should go off or household members may experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel unusually tired, leave the home right away and then call for help.
- Soot: If you notice black sooty buildup on the exterior of your furnace, it’s more evidence something might be seriously wrong.
What You Can Do if Your Furnace Heat Exchanger is Cracked
If you worry your furnace has a cracked heat exchanger, hire a pro experienced in furnace installation right away so they can inspect your system and, if necessary, start a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
However, the good news is that heat exchangers are generally covered by the warranty. You’ll want to review the warranty paperwork on your furnace, as 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 prevent a problem in your furnace overall is via routine furnace maintenance. Furnaces offer the most benefits when they run efficiently. Contacting a skilled professional to examine your furnace for broken-down parts, dirty filters and other potential 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 replaced 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 do its job. And the harder your furnace needs to run, the more strain parts like the heat exchanger will endure.