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

One root cause may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to familiarize yourself with the evidence of a cracked heat exchanger and what you should do if you suspect that is 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 flows inside the ventilation. It usually accomplishes this with coils or tubes that heat up 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? 

Because of its key role, it’s no surprise that a damaged heat exchanger can be hazardous. Cracks in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to circulate throughout your home. 

For this reason, never use your heater if you believe it has a cracked heat exchanger, as doing so could make your entire family ill. Reach out to an HVAC professional right away if you think your heater has a cracked heat exchanger that should be repaired. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace shuts off: A crack in your heat exchanger could cause your furnace to shut off. 
  • Unusual Smells: If the air coming out of your furnace has an intense chemical scent, it may be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a major warning sign. 
  • Carbon monoxide alarm initiates or you notice health problems: If a cracked heat exchanger is releasing carbon monoxide into your home, your carbon monoxide alarm should go off or household members could experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unwell, exit the home immediately and then call for help. 
  • Soot: If you spot black sooty accumulating around the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked 

If you worry your furnace has a cracked heat exchanger, call a professional with extensive experience in furnace installation Savage as soon as possible so they can examine your system and, if necessary, perform a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

However, the good news is that heat exchangers are regularly included in 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 can significantly reduce your bill.  

How to Avoid a Cracked Heat Exchanger in Your Home  

One of the easiest ways to prevent a problem in your furnace overall is through routine furnace maintenance. Furnaces provide the best possible return on investment when they operate efficiently. Hiring a trained professional to check your furnace for broken-down parts, clogs in the air filters and other potential problems can keep you from 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 encouraged some filters be replaced every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to the heat exchanger itself, the strain of drawing air through a clogged filter makes the entire furnace work harder to accomplish its job. And the harder your furnace works, the more wear and tear pieces like the heat exchanger will sustain.