A furnace is almost always a background player in your home, ensuring you're warm during the cold winter months. It often won't be noticed until a malfunction appears. 

One root cause might be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s critical to know the symptoms of a cracked heat exchanger and what to do if you believe that may 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 throughout the ventilation. It typically handles this with coils or tubes that heat the air while acting as a barrier to keep byproducts formed in the combustion chamber, called flue gasses, from getting out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Given its important role, it shouldn't come as a surprise that a broken heat exchanger can pose a risk. Cracks in the heat exchanger can enable dangerous gasses – including carbon monoxide, which can be lethal – to circulate throughout your home. 

For obvious reasons, do NOT run your heater if you think it has a cracked heat exchanger, as this could make the entire family sick. Reach out to an HVAC professional right away if you are worried your heater has a cracked heat exchanger that needs repair. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace switches off: Cracks in the heat exchanger can cause your furnace to switch off. 
  • Odd Smells: If the air escaping your furnace has an intense chemical scent, it may be evidence gasses are leaking through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a significant warning sign. 
  • Carbon monoxide alarm initiates or you notice poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members could start experiencing signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel sick, leave the home immediately and then call for help. 
  • Soot: If you spot black sooty accumulating around the exterior of your furnace, it’s more evidence something could be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked 

If you believe your furnace has a cracked heat exchanger, contact a pro experienced in furnace installation Omaha as soon as possible so they can inspect your system and, if needed, start a furnace heat exchanger replacement. Costs often fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

Fortunately, the good news is that heat exchangers are often covered by the warranty. You’ll want to review the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it still may significantly reduce your bill.  

How to Avoid a Cracked Heat Exchanger in Your Home  

One of the best ways to avoid problems in your furnace overall is via regular furnace maintenance. Furnaces work the best when they operate efficiently. Hiring a skilled professional to inspect your furnace for old parts, dirty filters and other common problems can keep you from getting a big bill later on.  

It’s also beneficial 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 pulling air through a clogged filter makes your entire furnace work more vigorously to do its job. And the harder your furnace needs to run, the more deterioration components like the heat exchanger will sustain.