A furnace is almost always a background player in your home, ensuring you're warm in the cold winter months. It often doesn’t get noticed until a malfunction appears. 

One root cause might be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s important to know the symptoms of a cracked heat exchanger and what to do if you are worried 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 inside the system. It usually handles this via coils or tubes that heat the air while acting 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? 

Given its important role, it shouldn't come as a surprise that a damaged heat exchanger can be very dangerous. A crack in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to circulate across your home. 

For that reason, never use your heater if you believe there's a crack in the heat exchanger, as this could make your entire family sick. Reach out to an HVAC professional immediately if you believe your heater has a cracked heat exchanger that should be repaired. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace shuts off: A cracked heat exchanger may cause your furnace to shut off. 
  • Odd Smells: If the air coming out of your furnace has an intense chemical smell, it might be an indicator that gasses are seeping through cracks in your heat exchanger. These byproducts, which may smell like formaldehyde, are a significant warning sign. 
  • Carbon monoxide alarm initiates or you recognize health problems: If a cracked heat exchanger is relieving carbon monoxide into your home, your carbon monoxide alarm may go off or household members may experience signs of carbon monoxide poisoning. Symptoms include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unusually tired, get out of the home immediately and then call for help. 
  • Soot: If you see black sooty accumulating on the exterior of your furnace, it’s an indication 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, contact a professional experienced in furnace installation Erie as soon as possible so they can inspect your system and, if necessary, handle a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates often hover around $1,000 to $3,000. 

Fortunately, the good news is that heat exchangers are generally included in the warranty. It's a good idea to confirm the warranty paperwork on your furnace, because while the warranty might not cover the entire cost of repairs, it could significantly lower 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 routine furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Contacting a skilled professional to check your furnace for old parts, clogs in the air 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 recommended 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 pulling air through a clogged filter makes your entire furnace work harder to accomplish its job. And the harder your furnace has to work, the more wear and tear components like the heat exchanger will endure.