A furnace is often a background player at home, helping keep you warm across the cold winter months. It often isn't noticed until something goes wrong.
One root cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to know the evidence of a cracked heat exchanger and what you can do if you are worried that might be 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 circulates inside the air ducts. It generally does this with coils or tubes that warm the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from leaking out into your home.
Is a Cracked Heat Exchanger Dangerous?
Because of its central role, it shouldn't come as a surprise that a broken heat exchanger can be very dangerous. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed throughout your home.
For that reason, don't ever use your heating if you think you're dealing with a cracked heat exchanger, as doing so could make the entire household sick. Contact an HVAC professional immediately if you think your furnace has a cracked heat exchanger that needs to be repaired.
Four Signs of a Cracked Heat Exchanger:
- Furnace switches off: Cracks in the heat exchanger can cause your furnace to shut off.
- Unusual Smells: If the air leaving your furnace has a strong chemical smell, it may be an indicator that gas is slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm initiates or you notice poisoning symptoms: 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. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unusually tired, exit the home right away and then call for help.
- Soot: If you spot black sooty buildup near the exterior of your furnace, it’s another sign something may be seriously wrong.
What You Should Do if the Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, hire a professional with extensive experience in furnace installation right away so they can inspect your system and, if necessary, start 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 often included in the warranty. You should review the warranty paperwork on your furnace, as while the warranty might not cover the entire cost of repairs, it can significantly shrink your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the most convenient ways to minimize the risk of problems in your furnace overall is through routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Contacting a skilled professional to examine your furnace for broken-down parts, clogged filters and other likely problems can help you avoid getting a big bill later on.
It’s also helpful to review 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 dragging air through a clogged filter makes your entire furnace work longer to accomplish its job. And the harder your furnace works, the more deterioration pieces like the heat exchanger will experience.