A furnace is often a background player in your home, ensuring you're warm in the cold winter months. It often doesn’t get noticed until something goes wrong.
One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the signs of a cracked heat exchanger and what you can do if you are worried that may be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger transfers heat from the combustion chamber in your furnace to the air that moves inside the system. It generally handles this using coils or tubes that warm the air while serving as a barrier to keep gas created in the combustion chamber, called flue gasses, from getting out into your home.
Is a Cracked Heat Exchanger Dangerous?
Given its central role, it shouldn't come as a surprise that a broken heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed through your home.
For obvious reasons, don't ever use your heating if you believe there's a crack in the heat exchanger, as doing so could make the entire family sick. Call an HVAC professional right away if you think your heating has a cracked heat exchanger that should be repaired.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace switches off: Cracks in the heat exchanger may cause your furnace to switch off.
- Odd Smells: If the air coming out of your furnace has a powerful chemical odor, it may be an indicator that gasses are seeping 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 notice health problems: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm may go off or household members could experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel sick, leave the home immediately and then call for help.
- Soot: If you find black sooty collecting on the exterior of your furnace, it’s another sign something could be seriously wrong.
What You Should Do if the Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, hire a professional with extensive experience 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 often differ depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.
However, the good news is that heat exchangers are generally included in the warranty. You’ll want to confirm the warranty paperwork on your furnace, as while the warranty won't always cover the entire cost of repairs, it still may significantly reduce 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 consistent furnace maintenance. Furnaces offer the most benefits when they work efficiently. Calling a certified professional to examine your furnace for worn-out parts, dirty filters and other potential problems can keep you from getting a big bill later on.
It’s also a good idea to take a look at 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 drawing air through a clogged filter makes your entire furnace work longer to complete its job. And the harder your furnace works, the more strain pieces like the heat exchanger will sustain.