A furnace is almost always a background player at home, helping keep you warm in the cold winter months. It often doesn’t get noticed until a malfunction appears. 

One root cause could 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 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 of your furnace to the air that moves inside the air ducts. It typically handles this via coils or tubes that warm the air while acting as a barrier to keep byproducts created in the combustion chamber, called flue gasses, from escaping out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Thanks to its central role, it shouldn't come as a surprise that a cracked heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to circulate across your home. 

For obvious reasons, do NOT turn on your furnace if you think you're dealing with a cracked heat exchanger, as this could make the entire family ill. Call an HVAC professional right away if you think your furnace has a cracked heat exchanger that should be repaired. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace shuts off: A crack in your heat exchanger may cause your furnace to turn off. 
  • Unusual Smells: If the air escaping your furnace has a strong chemical scent, it could be evidence gas is leaking through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a significant warning sign. 
  • Carbon monoxide alarm is triggered or you recognize symptoms of poisoning: If a cracked heat exchanger is relieving carbon monoxide in your home, your carbon monoxide alarm could go off or household members may start experiencing signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel sick, exit the home right away and then call for help. 
  • Soot: If you notice black sooty buildup around the exterior of your furnace, it’s an indication something could be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, contact a pro well versed in furnace installation West Valley City as soon as possible so they can examine your system and, if required, handle a furnace heat exchanger replacement. Costs often vary depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000. 

Fortunately, the good news is that heat exchangers are regularly covered by the warranty. It's a good idea to check the warranty paperwork on your furnace, as while the warranty won't always cover the entire cost of repairs, it still may significantly lower your bill.  

How to Avoid a Cracked Heat Exchanger in Your Home  

One of the best ways to prevent a problem in your furnace overall is with routine furnace maintenance. Furnaces provide the best possible return on investment when they work efficiently. Calling a skilled professional to check your furnace for old parts, dirty filters and other potential 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 swapped out 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 harder to do its job. And the harder your furnace works, the more wear and tear components like the heat exchanger will sustain.