A furnace is often a background player in your home, ensuring you're warm across the cold winter months. It frequently isn't noticed until something goes wrong. 

One source might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the evidence of a cracked heat exchanger and what you should do if you are worried that is the problem.  

What Is a Heat Exchanger in a Furnace? 

A heat exchanger transfers heat from the combustion chamber in your furnace to the air that moves throughout the air ducts. It generally accomplishes this with coils or tubes that warm the air while acting as a barrier to keep byproducts formed 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 isn't surprising that a damaged heat exchanger can be hazardous. A crack in the heat exchanger can allow dangerous gasses – like carbon monoxide, which can be lethal – to be distributed throughout your home. 

For obvious reasons, don't ever turn on your furnace if you think there's a crack in the heat exchanger, as letting it run could make your entire household ill. Contact an HVAC professional right away if you are worried your heating has a cracked heat exchanger that needs to be repaired. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace switches off: A cracked heat exchanger may cause your furnace to shut off. 
  • Unusual Smells: If the air leaving your furnace has a strong chemical smell, it may be an indicator that gasses are slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a significant warning sign. 
  • Carbon monoxide alarm initiates or you recognize symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm could go off or family members might start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel unusually tired, leave the home as soon as you can and then call for help. 
  • Soot: If you notice black sooty collecting on the exterior of your furnace, it’s more evidence something may be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked 

If you believe your furnace has a cracked heat exchanger, call a professional with extensive experience in furnace installation Wilkes Barre and Scranton as soon as possible so they can examine your system and, if needed, start a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

Fortunately, the good news is that heat exchangers are generally included in the warranty. It's a good idea to check the warranty paperwork on your furnace, as while the warranty might not cover the entire cost of repairs, it can significantly lower your bill.  

How to Prevent a Cracked Heat Exchanger in Your Home  

One of the most convenient ways to avoid problems in your furnace overall is via regular furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Calling a certified 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 review 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 are not part of the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work longer to do its job. And the harder your furnace needs to run, the more strain components like the heat exchanger will experience.