A furnace is usually a background player in your home, ensuring you're warm across the cold winter months. It regularly won't be noticed until a malfunction appears.
One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to learn the evidence of a cracked heat exchanger and what you should do if you are worried that is 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 system. It typically accomplishes this with coils or tubes that heat the air while serving 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?
Thanks to its key role, it shouldn't come as a surprise that a broken heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home.
For obvious reasons, don't ever run your furnace if you think there's a crack in the heat exchanger, as doing so could make the whole household sick. Contact an HVAC professional as soon as possible if you believe your furnace has a cracked heat exchanger that needs repair.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace turns off: Cracks in the heat exchanger may cause your furnace to turn off.
- Odd Smells: If the air leaving your furnace has an intense chemical odor, it could be evidence gasses are leaking through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm initiates or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members could experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If the alarm goes off or you feel unusually tired, leave the home right away and then call for help.
- Soot: If you find black sooty collecting on the exterior of your furnace, it’s more evidence something may be seriously wrong.
What You Can Do if the Furnace Heat Exchanger is Cracked
If you believe your furnace has a cracked heat exchanger, hire a pro well versed in furnace installation right away so they can examine your system and, if required, start a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are generally protected by the warranty. It's a good idea to review the warranty paperwork on your furnace, because 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 easiest ways to avoid problems in your furnace overall is via consistent furnace maintenance. Furnaces offer the most benefits when they run efficiently. Calling a trained professional to examine your furnace for broken-down parts, clogs in the air filters and other common problems can keep you from getting a big bill later on.
It’s also helpful 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 pulling air through a clogged filter makes the entire furnace work more vigorously to accomplish its job. And the harder your furnace has to work, the more strain components like the heat exchanger will experience.