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 source may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to learn the evidence of a cracked heat exchanger and what to do if you are worried that might be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger transfers heat from the combustion chamber of your furnace to the air that circulates inside the ventilation. It generally does this through coils or tubes that heat the air while serving as a barrier to keep the gasses created in the combustion chamber, called flue gasses, from escaping out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its central role, it shouldn't come as a surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to circulate through your home.
For this reason, don't ever turn on your heater if you believe it has a cracked heat exchanger, as this could make the entire family sick. Reach out to an HVAC professional right away if you believe your furnace has a cracked heat exchanger that needs to be repaired.
Four Signs of a Cracked Heat Exchanger:
- Furnace turns off: Cracks in the heat exchanger could cause your furnace to switch off.
- Odd Smells: If the air escaping your furnace has a powerful chemical scent, it could be a sign gasses are leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm is triggered or you recognize poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm may go off or household members might struggle with signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel sick, leave the home immediately and then call for help.
- Soot: If you spot black sooty buildup on the exterior of your furnace, it’s another sign something could be seriously wrong.
What to Do if Your Furnace Heat Exchanger is Cracked
If you believe your furnace has a cracked heat exchanger, hire a professional well versed in furnace installation right away so they can take a look at your system and, if necessary, start a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000.
However, the good news is that heat exchangers are often covered by the warranty. You’ll want to review the warranty paperwork on your furnace, since while the warranty won't always cover the entire cost of repairs, it could significantly lower your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the best ways to avoid problems in your furnace overall is via regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Calling a skilled professional to check your furnace for broken-down parts, dirty filters and other potential 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 are not part of the heat exchanger itself, the strain of pulling air through a clogged filter makes your entire furnace work more vigorously to complete its job. And the harder your furnace needs to run, the more strain parts like the heat exchanger will experience.
