A furnace is usually a background player for your home, keeping you warm in the cold winter months. It regularly doesn’t get noticed until something goes wrong. 

One root cause could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s critical to learn 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 transition heat from the combustion chamber inside your furnace to the air that moves inside the system. It generally does this using coils or tubes that heat up the air while functioning as a barrier to keep the gasses created 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 isn't surprising that a cracked heat exchanger can be very dangerous. A damaged heat exchanger can allow dangerous gasses – including carbon monoxide, which can be lethal – to be distributed across your home. 

For this reason, never run your heater if you suspect there's a crack in the heat exchanger, as doing so could make the entire household sick. Contact an HVAC professional right away if you believe your heater has a cracked heat exchanger that needs repair. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace turns off: A crack in your heat exchanger can cause your furnace to turn off. 
  • Strange Smells: If the air leaving your furnace has a strong chemical odor, it may be evidence gasses are slipping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a common warning sign. 
  • Carbon monoxide alarm goes off or you notice symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide in your home, your carbon monoxide alarm should go off or household members might experience signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If the alarm goes off or you feel unwell, get out of the home immediately and then call for help. 
  • Soot: If you see black sooty accumulating around the exterior of your furnace, it’s another sign something may be seriously wrong.

What to Do if Your Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, call a professional well versed in furnace installation Georgetown as soon as possible so they can examine your system and, if necessary, handle a furnace heat exchanger replacement. Costs should 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 protected by the warranty. It's a good idea to check the warranty paperwork on your furnace, because while the warranty might not 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 via consistent furnace maintenance. Furnaces offer the most benefits when they run efficiently. Calling a skilled professional to inspect your furnace for broken-down parts, clogged filters and other potential 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 recommended some filters be swapped out 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 pulling 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 pieces like the heat exchanger will experience.