A furnace is almost always a background player at home, ensuring you're warm during the cold winter months. It regularly doesn’t get noticed until a malfunction appears.
One cause could be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s important to learn the symptoms of a cracked heat exchanger and what you should do if you are worried that might be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps move heat from the combustion chamber of your furnace to the air that flows inside the air ducts. It typically accomplishes this via coils or tubes that heat up the air while functioning as a barrier to keep gas created in the combustion chamber, called flue gasses, from leaking out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its key role, it shouldn't come as a surprise that a cracked heat exchanger can pose a risk. A damaged heat exchanger can enable dangerous gasses – including carbon monoxide, which can be lethal – to flow through your home.
For this reason, never use your heater if you think you're dealing with a cracked heat exchanger, as doing so could make your entire family sick. Call an HVAC professional as soon as possible if you are worried your furnace has a cracked heat exchanger that should be repaired.
Four Signs of a Cracked Heat Exchanger:
- Furnace shuts off: Cracks in the heat exchanger may cause your furnace to turn off.
- Unusual Smells: If the air escaping your furnace has a strong chemical odor, it could be an indicator that gas is seeping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm initiates or you feel health problems: If a cracked heat exchanger is emitting 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 drowsy. If the alarm goes off or you feel unusually tired, leave the home as soon as you can and then call for help.
- Soot: If you spot black sooty collecting around the exterior of your furnace, it’s an indication something may be seriously wrong.
What You Can Do if a Furnace Heat Exchanger is Cracked
If you worry your furnace has a cracked heat exchanger, contact a pro experienced in furnace installation right away so they can inspect your system and, if necessary, handle a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are generally included in the warranty. You’ll want to check the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it still may significantly shrink your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the easiest ways to minimize the risk of problems in your furnace overall is with regular furnace maintenance. Furnaces offer the most benefits when they run efficiently. Calling a certified professional to check your furnace for old parts, dirty 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 encouraged some filters be replaced 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 the entire furnace work harder to accomplish its job. And the harder your furnace needs to run, the more deterioration components like the heat exchanger will endure.