A furnace is usually a background player in your home, helping keep you warm in the cold winter months. It regularly isn't noticed until a malfunction appears.
One cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s worthwhile to learn the evidence of a cracked heat exchanger and what to do if you believe that may be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps transition heat from the combustion chamber in your furnace to the air that moves throughout the ventilation. It typically handles this with coils or tubes that heat the air while functioning as a barrier to keep the gasses produced in the combustion chamber, called flue gasses, from leaking out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its central role, it isn't surprising that a damaged heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to circulate through your home.
For that reason, do NOT turn on your heater if you believe you're dealing with a cracked heat exchanger, as this could make the whole family sick. Call an HVAC professional right away if you believe your furnace has a cracked heat exchanger that should be repaired.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace turns off: A crack in your heat exchanger could cause your furnace to switch off.
- Strange Smells: If the air coming out of your furnace has a powerful chemical smell, it may be a sign gasses are slipping through cracks in your heat exchanger. These gasses, which will often smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm is triggered or you recognize health problems: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm could go off or family members might start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, leave the home right away and then call for help.
- Soot: If you see black sooty buildup near the exterior of your furnace, it’s another sign something might be seriously wrong.
What You Can Do if a Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, call a pro experienced in furnace installation as soon as possible so they can examine your system and, if necessary, handle a furnace heat exchanger replacement. Costs often differ depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.
Estimates aside, the good news is that heat exchangers are regularly included in the warranty. You’ll want to review the warranty paperwork on your furnace, since while the warranty might not 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 easiest ways to avoid problems in your furnace overall is via regular furnace maintenance. Furnaces work the best when they work efficiently. Hiring a trained professional to inspect 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 beneficial to inspect your furnace filters every few months – it’s ideal 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 dragging air through a clogged filter makes your entire furnace work more vigorously to complete its job. And the harder your furnace works, the more wear and tear parts like the heat exchanger will endure.