A furnace is usually a background player in your home, keeping you warm during the cold winter months. It frequently isn't noticed until a malfunction appears. 

One cause could be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to learn the symptoms of a cracked heat exchanger and what you should do if you believe that is 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 moves through the ventilation. It usually accomplishes this via coils or tubes that heat the air while serving as a barrier to keep byproducts formed in the combustion chamber, called flue gasses, from escaping out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Because of its important role, it’s no surprise that a broken heat exchanger can be hazardous. Cracks in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home. 

For this reason, do NOT turn on your heating if you believe you're dealing with a cracked heat exchanger, as letting it run could make your entire family ill. Contact an HVAC professional as soon as possible if you think your heater has a cracked heat exchanger that should be repaired. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace turns off: A cracked heat exchanger could cause your furnace to turn off. 
  • Odd Smells: If the air escaping your furnace has a strong chemical odor, it could be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which will often 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 in your home, your carbon monoxide alarm should go off or family members may start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If an alarm goes off or you feel unusually tired, exit the home as soon as you can and then call for help. 
  • Soot: If you notice black sooty accumulating on the exterior of your furnace, it’s an indication something could be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, hire a pro well versed in furnace installation Payson as soon as possible so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs often 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 generally covered by the warranty. You’ll want to check the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it could significantly reduce your bill.  

How to Avoid a Cracked Heat Exchanger in Your Home  

One of the most convenient ways to prevent a problem in your furnace overall is through consistent furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a trained professional to check your furnace for worn-out parts, clogged 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 encouraged 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 dragging air through a clogged filter makes your entire furnace work more vigorously to complete its job. And the harder your furnace needs to run, the more wear and tear parts like the heat exchanger will endure.