A furnace is often a background player at home, ensuring you're warm across the cold winter months. It regularly won't be noticed until something breaks down.
One root cause could be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to learn the symptoms of a cracked heat exchanger and what you can do if you suspect that may 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 through the system. It generally handles this using coils or tubes that heat the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from escaping out into your home.
Is a Cracked Heat Exchanger Dangerous?
Thanks to its important role, it’s no surprise that a damaged heat exchanger can pose a risk. Cracks in the heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to flow throughout your home.
For obvious reasons, never turn on your heater if you think you're dealing with a cracked heat exchanger, as doing so could make the entire household sick. Contact an HVAC professional as soon as possible if you believe your heating has a cracked heat exchanger that should be repaired.
Four Symptoms of a Cracked Heat Exchanger:
- Furnace turns off: Cracks in the heat exchanger could cause your furnace to shut off.
- Odd Smells: If the air coming out of your furnace has a strong chemical smell, it may be evidence gasses are slipping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a common warning sign.
- Carbon monoxide alarm initiates or you notice symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm may go off or household members could experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel sick, leave the home as soon as you can and then call for help.
- Soot: If you see black sooty buildup near the exterior of your furnace, it’s an indication something could be seriously wrong.
What You Should Do if a Furnace Heat Exchanger is Cracked
If you suspect your furnace has a cracked heat exchanger, hire a professional with extensive experience in furnace installation as soon as possible so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates often hover around $1,000 to $3,000.
Estimates aside, the good news is that heat exchangers are regularly included in the warranty. It's a good idea to check the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it still may significantly shrink your bill.
How to Avoid a Cracked Heat Exchanger in Your Home
One of the most convenient ways to minimize the risk of problems in your furnace overall is with regular furnace maintenance. Furnaces offer the most benefits when they work efficiently. Hiring a certified professional to inspect your furnace for broken-down parts, dirty filters and other common problems can help you avoid getting a big bill later on.
It’s also a good idea to take a look at 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 dragging air through a clogged filter makes the entire furnace work more vigorously to complete its job. And the harder your furnace works, the more wear and tear components like the heat exchanger will experience.