A furnace is often a background player for your home, helping keep you warm during the cold winter months. It often won't be noticed until a malfunction appears. 

One cause may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, 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 inside your furnace to the air that flows throughout the system. It typically handles this through coils or tubes that warm the air while serving as a barrier to keep byproducts 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 isn't surprising that a cracked heat exchanger can pose a risk. A crack in the heat exchanger can enable dangerous gasses – like carbon monoxide, which can be lethal – to flow across your home. 

For this reason, do NOT turn on your heating if you suspect it has a cracked heat exchanger, as doing so could make the whole family sick. Contact an HVAC professional immediately if you believe your heating has a cracked heat exchanger that needs repair. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace switches off: Cracks in the heat exchanger may cause your furnace to turn off. 
  • Strange Smells: If the air escaping your furnace has an intense chemical smell, it might be a sign gas is slipping through cracks in your heat exchanger. These gasses, which can smell like formaldehyde, are a common warning sign. 
  • Carbon monoxide alarm initiates or you recognize symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm could go off or family members may experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel unwell, leave the home as soon as you can and then call for help. 
  • Soot: If you spot black sooty buildup around the exterior of your furnace, it’s more evidence something may be seriously wrong.

What to Do if Your Furnace Heat Exchanger is Cracked 

If you worry your furnace has a cracked heat exchanger, contact a professional with extensive experience in furnace installation Laurel right away so they can examine your system and, if required, perform a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000. 

Estimates aside, the good news is that heat exchangers are regularly covered by the warranty. You should review the warranty paperwork on your furnace, because while the warranty won't always 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 easiest ways to avoid problems in your furnace overall is with regular furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a skilled professional to check your furnace for old parts, clogs in the air filters and other likely 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 ideal some filters be replaced 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 drawing air through a clogged filter makes the entire furnace work longer to accomplish its job. And the harder your furnace needs to run, the more deterioration pieces like the heat exchanger will endure.