A furnace is almost always a background player at home, ensuring you're warm in the cold winter months. It frequently isn't noticed until something breaks down. 

One cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to learn the evidence of a cracked heat exchanger and what to 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 throughout the air ducts. It typically does this with coils or tubes that warm the air while acting as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from leaking out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Thanks to its key role, it’s no surprise that a cracked heat exchanger can pose a risk. A crack in the heat exchanger can allow dangerous gasses – like carbon monoxide, which can be lethal – to flow through your home. 

For obvious reasons, do NOT turn on your furnace if you think you're dealing with a cracked heat exchanger, as letting it run could make the whole household sick. Reach out to an HVAC professional immediately if you think your furnace has a cracked heat exchanger that needs repair. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace switches off: A cracked heat exchanger can cause your furnace to shut off. 
  • Odd Smells: If the air leaving your furnace has a strong chemical odor, it might be an indicator that gasses are leaking through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign. 
  • Carbon monoxide alarm goes off or you feel symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm should go off or family members may start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel unusually tired, exit the home immediately and then call for help. 
  • Soot: If you find black sooty accumulating around the exterior of your furnace, it’s more evidence something could be seriously wrong.

What to Do if a Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, contact a professional with extensive experience in furnace installation Hudsonville right away so they can take a look at your system and, if required, handle a furnace heat exchanger replacement. Costs often differ depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

However, the good news is that heat exchangers are regularly protected by the warranty. It's a good idea to review the warranty paperwork on your furnace, as while the warranty may not cover the entire cost of repairs, it could significantly reduce 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 routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Contacting a certified professional to check your furnace for worn-out parts, clogged filters and other likely problems can keep you from getting a big bill later on.  

It’s also a good idea to inspect your furnace filters every few months – it’s encouraged some filters be replaced 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 dragging air through a clogged filter makes your entire furnace work longer to complete its job. And the harder your furnace has to work, the more deterioration pieces like the heat exchanger will endure.