A furnace is often a background player for your home, ensuring you're warm across the cold winter months. It frequently isn't noticed until something goes wrong.
One cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the signs of a cracked heat exchanger and what you should do if you suspect that may be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps transition heat from the combustion chamber inside your furnace to the air that moves throughout the system. It usually handles this via 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 leaking 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 very dangerous. A crack in the heat exchanger can allow dangerous gasses – like carbon monoxide, which can be lethal – to flow throughout your home.
For this reason, never use your heating if you think you're dealing with a cracked heat exchanger, as this could make your entire family sick. Reach out to an HVAC professional right away if you think your heater has a cracked heat exchanger that needs to be repaired.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace shuts off: A cracked heat exchanger may cause your furnace to turn off.
- Strange Smells: If the air leaving your furnace has a powerful chemical scent, it could be an indicator that gas is slipping through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm may go off or family members could start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel sick, exit the home immediately and then call for help.
- Soot: If you see black sooty collecting on the exterior of your furnace, it’s an indication something could 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 professional experienced in furnace installation right away so they can inspect your system and, if required, handle a furnace heat exchanger replacement. Costs often differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
However, the good news is that heat exchangers are often protected by the warranty. You should review the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it can 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 with routine furnace maintenance. Furnaces work the best when they operate efficiently. Hiring a trained professional to examine your furnace for broken-down parts, clogs in the air filters and other likely problems can help you avoid getting a big bill later on.
It’s also a good idea to take a look at 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 dragging air through a clogged filter makes the entire furnace work harder to complete its job. And the harder your furnace has to work, the more wear and tear pieces like the heat exchanger will sustain.