A furnace is often a background player in your home, ensuring you're warm across the cold winter months. It frequently doesn’t get noticed until a malfunction appears.
One source could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to know the evidence of a cracked heat exchanger and what you should 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 inside your furnace to the air that circulates through the ventilation. It typically accomplishes this with coils or tubes that heat up the air while serving as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from getting out into your home.
Is a Cracked Heat Exchanger Dangerous?
Because of 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 allow dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.
For obvious reasons, don't ever run your heater if you think it has a cracked heat exchanger, as letting it run could make your entire family ill. Call an HVAC professional immediately if you are worried your heating has a cracked heat exchanger that needs repair.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace shuts off: A crack in your heat exchanger can cause your furnace to turn off.
- Strange Smells: If the air coming out of your furnace has a powerful chemical odor, it could be evidence gas is slipping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm initiates or you notice symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm may go off or family members could experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unwell, leave the home as soon as you can and then call for help.
- Soot: If you see black sooty collecting around the exterior of your furnace, it’s another sign something might be seriously wrong.
What You Can Do if the Furnace Heat Exchanger is Cracked
If you worry your furnace has a cracked heat exchanger, contact a pro with extensive experience in furnace installation as soon as possible so they can examine your system and, if needed, handle a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $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, because while the warranty might not cover the entire cost of repairs, it could significantly reduce your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the easiest ways to avoid problems in your furnace overall is with consistent furnace maintenance. Furnaces work the best when they operate efficiently. Calling a certified professional to examine your furnace for old parts, dirty filters and other common problems can keep you from getting a big bill later on.
It’s also a good idea to inspect your furnace filters every few months – it’s encouraged some filters be swapped out every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work longer to do its job. And the harder your furnace needs to run, the more deterioration parts like the heat exchanger will experience.