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

One cause might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to familiarize yourself with the evidence of a cracked heat exchanger and what you should do if you suspect that may be the problem.  

What Is a Heat Exchanger in a Furnace? 

A heat exchanger helps transition heat from the combustion chamber of your furnace to the air that moves through the system. It generally handles this using coils or tubes that heat the air while serving as a barrier to keep the gasses 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’s no surprise that a broken heat exchanger can pose a risk. A crack in the heat exchanger can enable dangerous gasses – such as carbon monoxide, which can be lethal – to circulate across your home. 

For obvious reasons, never turn on your furnace if you believe it has a cracked heat exchanger, as doing so could make the whole household ill. Reach out to an HVAC professional as soon as possible if you believe your furnace has a cracked heat exchanger that needs repair. 

Four Warning Signs of a Cracked Heat Exchanger: 

  • Furnace turns off: Cracks in the heat exchanger may cause your furnace to shut off. 
  • Strange Smells: If the air escaping your furnace has an intense chemical odor, it could be evidence gas is seeping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a major warning sign. 
  • Carbon monoxide alarm goes off or you feel symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members might struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If your alarm goes off or you feel unusually tired, exit the home immediately and then call for help. 
  • Soot: If you spot black sooty collecting near the exterior of your furnace, it’s an indication something could be seriously wrong.

What You Can 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 Crown Point right away so they can examine your system and, if necessary, start a furnace heat exchanger replacement. Costs will vary depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

Estimates aside, the good news is that heat exchangers are regularly covered by the warranty. You should confirm the warranty paperwork on your furnace, since while the warranty may not cover the entire cost of repairs, it can significantly shrink your bill.  

How to Prevent a Cracked Heat Exchanger in Your Home  

One of the most convenient ways to minimize the risk of problems in your furnace overall is through regular furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Hiring a trained professional to examine your furnace for worn-out parts, dirty filters and other likely problems can keep you from getting a big bill later on.  

It’s also helpful 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 drawing air through a clogged filter makes your entire furnace work more vigorously to complete its job. And the harder your furnace has to work, the more wear and tear components like the heat exchanger will endure.