A furnace is usually a background player in your home, keeping you warm across the cold winter months. It frequently won't be noticed until something breaks down.
One source could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s worthwhile to learn the signs of a cracked heat exchanger and what you should do if you believe that is the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger transfers heat from the combustion chamber inside your furnace to the air that flows throughout the system. It generally accomplishes this through 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?
Given its important role, it’s no surprise that a damaged heat exchanger can be hazardous. A crack in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to circulate through your home.
For that reason, don't ever run your heater if you think there's a crack in the heat exchanger, as doing so could make your entire household sick. Call an HVAC professional right away if you believe your furnace has a cracked heat exchanger that should be repaired.
Four Warning Signs of a Cracked Heat Exchanger:
- Furnace switches off: A cracked heat exchanger can cause your furnace to shut off.
- Unusual Smells: If the air leaving your furnace has a powerful chemical scent, it might be a sign gasses are leaking through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a major warning sign.
- Carbon monoxide alarm initiates or you feel health problems: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm may 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 unwell, exit the home immediately and then call for help.
- Soot: If you find black sooty accumulating around the exterior of your furnace, it’s an indication something could be seriously wrong.
What to Do if Your Furnace Heat Exchanger is Cracked
If you worry your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation The Bay Area as soon as possible so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000.
However, the good news is that heat exchangers are regularly covered by 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 reduce your bill.
How to Prevent a Cracked Heat Exchanger in Your Home
One of the easiest ways to minimize the risk of problems in your furnace overall is with routine furnace maintenance. Furnaces offer the most benefits when they work efficiently. Hiring a certified professional to check your furnace for old parts, clogs in the air filters and other potential problems can keep you from getting a big bill later on.
It’s also helpful to review your furnace filters every few months – it’s recommended 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 drawing air through a clogged filter makes your entire furnace work harder to do its job. And the harder your furnace has to work, the more strain pieces like the heat exchanger will endure.