A furnace is often a background player for your home, keeping you warm in the cold winter months. It regularly won't be noticed until something breaks down.
One cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to familiarize yourself with the symptoms of a cracked heat exchanger and what to do if you are worried that is 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 circulates through the air ducts. It generally handles this via coils or tubes that warm the air while serving 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?
Given its key role, it shouldn't come as a 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 obvious reasons, don't ever use your heater if you believe there's a crack in the heat exchanger, as doing so could make the entire family sick. Contact an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that needs to be repaired.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace switches off: Cracks in the heat exchanger can cause your furnace to turn off.
- Strange Smells: If the air coming out of your furnace has a strong chemical smell, it may be an indicator that gasses are slipping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm initiates or you notice poisoning symptoms: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm should go off or family members could struggle with signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel sick, get out of the home right away and then call for help.
- Soot: If you see black sooty collecting near the exterior of your furnace, it’s an indication something may be seriously wrong.
What to Do if a Furnace Heat Exchanger is Cracked
If you worry your furnace has a cracked heat exchanger, contact a professional with extensive experience in furnace installation as soon as possible so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs will differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
Estimates aside, the good news is that heat exchangers are often included in the warranty. You’ll want to review the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it still may significantly lower your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the most convenient ways to avoid problems in your furnace overall is via routine furnace maintenance. Furnaces work the best when they run efficiently. Hiring a trained professional to check your furnace for worn-out parts, clogged filters and other likely problems can help you avoid getting a big bill later on.
It’s also beneficial to inspect 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 has to work, the more deterioration pieces like the heat exchanger will endure.