A furnace is often a background player for your home, keeping you warm during the cold winter months. It often doesn’t get noticed until a malfunction appears.
One source might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to know the evidence of a cracked heat exchanger and what you can do if you believe that might be the problem.
What Is a Heat Exchanger in a Furnace?
A heat exchanger helps move heat from the combustion chamber inside your furnace to the air that flows inside the ventilation. It typically does this via coils or tubes that heat up the air while serving as a barrier to keep the gasses created in the combustion chamber, called flue gasses, from getting out into your home.
Is a Cracked Heat Exchanger Dangerous?
Because of its important role, it’s no surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to be distributed through your home.
For this reason, don't ever use your furnace if you suspect there's a crack in the heat exchanger, as this could make the whole family ill. Contact an HVAC professional right away if you believe your heater has a cracked heat exchanger that needs repair.
Four Signs of a Cracked Heat Exchanger:
- Furnace turns off: A cracked heat exchanger could cause your furnace to switch off.
- Strange Smells: If the air coming out of your furnace has a powerful chemical odor, it could be evidence gasses are leaking through cracks in your heat exchanger. These gasses, 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 releasing carbon monoxide in your home, your carbon monoxide alarm should go off or household members may start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel unwell, exit the home immediately and then call for help.
- Soot: If you spot black sooty accumulating around the exterior of your furnace, it’s more evidence something might be seriously wrong.
What You Should Do if Your Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, call a professional well versed in furnace installation as soon as possible so they can inspect your system and, if necessary, handle a furnace heat exchanger replacement. Costs should vary depending on the situation, but estimates often hover around $1,000 to $3,000.
Fortunately, the good news is that heat exchangers are regularly included in the warranty. You’ll want to check the warranty paperwork on your furnace, because while the warranty may not cover the entire cost of repairs, it can significantly reduce your bill.
How to Avoid a Cracked Heat Exchanger in Your Home
One of the best ways to avoid problems in your furnace overall is through routine furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Hiring a trained professional to examine your furnace for old parts, clogged filters and other common 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 changed 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 the entire furnace work more vigorously to do its job. And the harder your furnace has to work, the more deterioration parts like the heat exchanger will sustain.