A furnace is often a background player in your home, ensuring you're warm across the cold winter months. It often isn't noticed until something breaks down. 

One root cause might be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to learn the symptoms of a cracked heat exchanger and what you should do if you are worried that might be the problem.  

What Is a Heat Exchanger in a Furnace? 

A heat exchanger helps transition heat from the combustion chamber inside your furnace to the air that flows through the ventilation. It typically handles this using coils or tubes that heat up the air while acting as a barrier to keep byproducts produced in the combustion chamber, called flue gasses, from escaping out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Given its key role, it isn't surprising that a cracked heat exchanger can be hazardous. A damaged heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to flow throughout your home. 

For that reason, never run your heating if you think you're dealing with a cracked heat exchanger, as letting it run could make your entire household ill. Call an HVAC professional right away if you are worried your furnace has a cracked heat exchanger that needs to be repaired. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace turns off: Cracks in the heat exchanger may cause your furnace to turn off. 
  • Odd Smells: If the air escaping your furnace has an intense chemical scent, it might be a sign gasses are 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 recognize health problems: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm should go off or household members might struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling tired. If your alarm goes off or you feel sick, exit the home as soon as you can and then call for help. 
  • Soot: If you spot black sooty collecting on the exterior of your furnace, it’s more evidence something might be seriously wrong.

What You Can Do if Your Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, hire a pro with extensive experience in furnace installation Edmond right away so they can take a look at your system and, if required, perform a furnace heat exchanger replacement. Costs should differ depending on the situation, but estimates often hover around $1,000 to $3,000. 

Estimates aside, the good news is that heat exchangers are generally 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 reduce 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 through regular furnace maintenance. Furnaces work the best when they operate efficiently. Contacting a trained professional to check your furnace for broken-down parts, dirty filters and other likely problems can help you avoid getting a big bill later on.  

It’s also helpful to review your furnace filters every few months – it’s ideal some filters be changed every 90 days or sooner if they are dirty or grimy. While the filters aren't a part of the heat exchanger itself, the strain of dragging air through a clogged filter makes your entire furnace work harder to complete its job. And the harder your furnace needs to run, the more deterioration parts like the heat exchanger will sustain.