A furnace is often a background player for your home, ensuring you're warm during the cold winter months. It often 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 worthwhile to learn the signs 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 helps move heat from the combustion chamber in your furnace to the air that flows inside the ventilation. It usually handles this via coils or tubes that warm the air while functioning as a barrier to keep gas created in the combustion chamber, called flue gasses, from escaping out into your home.
Is a Cracked Heat Exchanger Dangerous?
Because of its key role, it’s no surprise that a broken heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home.
For that reason, don't ever use your furnace if you think there's a crack in the heat exchanger, as letting it run could make your entire family ill. Reach out to an HVAC professional immediately if you are worried your heater has a cracked heat exchanger that needs repair.
Four Signs of a Cracked Heat Exchanger:
- Furnace shuts off: A cracked heat exchanger could cause your furnace to switch off.
- Strange Smells: If the air coming out of your furnace has an intense chemical odor, it may be evidence gas is leaking through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a significant warning sign.
- Carbon monoxide alarm goes off or you notice poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide in your home, your carbon monoxide alarm should go off or household members could experience signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel unusually tired, exit the home right away and then call for help.
- Soot: If you see black sooty buildup on the exterior of your furnace, it’s another sign something might be seriously wrong.
What You Can Do if a Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation right away so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs often vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000.
However, the good news is that heat exchangers are regularly protected by 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 lower your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the most convenient ways to prevent a problem in your furnace overall is via regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Contacting a skilled professional to examine your furnace for old parts, dirty filters and other common problems can help you avoid getting a big bill later on.
It’s also beneficial to take a look at your furnace filters every few months – it’s ideal 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 pulling air through a clogged filter makes the entire furnace work harder to do its job. And the harder your furnace needs to run, the more strain components like the heat exchanger will sustain.