A furnace is usually a background player at home, ensuring you're warm across the cold winter months. It often doesn’t get noticed until a malfunction appears.
One source could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to know the evidence of a cracked heat exchanger and what you should do if you suspect 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 generally handles this via coils or tubes that heat up the air while acting as a barrier to keep gas formed in the combustion chamber, called flue gasses, from escaping out into your home.
Is a Cracked Heat Exchanger Dangerous?
Because of its important role, it shouldn't come as a surprise that a damaged heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to circulate through your home.
For this reason, never use your furnace if you believe you're dealing with a cracked heat exchanger, as this could make the entire household sick. Call an HVAC professional as soon as possible if you are worried your heater has a cracked heat exchanger that needs repair.
Four Signs of a Cracked Heat Exchanger:
- Furnace switches off: A crack in your heat exchanger could cause your furnace to turn off.
- Odd Smells: If the air coming out of your furnace has a powerful chemical odor, it may be evidence gasses are leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is emitting carbon monoxide in 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 sleepy. If your alarm goes off or you feel unusually tired, get out of the home as soon as you can and then call for help.
- Soot: If you find black sooty accumulating near the exterior of your furnace, it’s an indication something could be seriously wrong.
What You Should Do if the Furnace Heat Exchanger is Cracked
If you believe your furnace has a cracked heat exchanger, call a pro well versed in furnace installation right away so they can take a look at your system and, if needed, perform a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates often hover around $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are generally covered by the warranty. You should check the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it can significantly reduce your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the easiest ways to prevent a problem in your furnace overall is via routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Calling a skilled professional to examine your furnace for broken-down parts, clogged filters and other common problems can help you avoid getting a big bill later on.
It’s also a good idea to review your furnace filters every few months – it’s recommended some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to the heat exchanger itself, the strain of drawing air through a clogged filter makes the entire furnace work harder to do its job. And the harder your furnace works, the more deterioration components like the heat exchanger will experience.