A furnace is often a background player for your home, ensuring you're warm during the cold winter months. It regularly isn't noticed until something goes wrong. 

One cause may be that your furnace has a cracked heat exchanger. It can be a safety risk, so it’s important to learn the signs of a cracked heat exchanger and what to do if you are worried that is the problem.  

What Is a Heat Exchanger in a Furnace? 

A heat exchanger transfers heat from the combustion chamber in your furnace to the air that flows inside the air ducts. It usually accomplishes this through coils or tubes that warm the air while functioning as a barrier to keep gas produced in the combustion chamber, called flue gasses, from getting out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Thanks to its central role, it shouldn't come as a surprise that a damaged heat exchanger can be hazardous. Cracks in the heat exchanger can permit dangerous gasses – like carbon monoxide, which can be lethal – to circulate throughout your home. 

For this reason, do NOT use your heater if you believe it has a cracked heat exchanger, as doing so could make the whole household ill. Reach out to an HVAC professional immediately if you think your heater has a cracked heat exchanger that needs to be repaired. 

Four Warning Signs of a Cracked Heat Exchanger: 

  • Furnace shuts off: Cracks in the heat exchanger could cause your furnace to turn off. 
  • Unusual Smells: If the air coming out of your furnace has a strong chemical odor, it could be an indicator that gas is leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign. 
  • Carbon monoxide alarm is triggered or you notice poisoning symptoms: If a cracked heat exchanger is relieving carbon monoxide inside your home, your carbon monoxide alarm could go off or family members might struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If an alarm goes off or you feel unusually tired, exit the home immediately and then call for help. 
  • Soot: If you spot black sooty accumulating on the exterior of your furnace, it’s an indication something might be seriously wrong.

What You Can Do if a Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, call a professional well versed in furnace installation Newark right away so they can inspect your system and, if necessary, perform a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

Fortunately, the good news is that heat exchangers are often covered by the warranty. It's a good idea to confirm the warranty paperwork on your furnace, because while the warranty won't always cover the entire cost of repairs, it still may significantly reduce your bill.  

How to Avoid a Cracked Heat Exchanger in Your Home  

One of the best ways to avoid problems in your furnace overall is with regular furnace maintenance. Furnaces offer the most benefits when they run efficiently. Hiring a certified professional to examine your furnace for broken-down parts, dirty filters and other likely problems can keep you from 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 replaced 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 do its job. And the harder your furnace has to work, the more strain parts like the heat exchanger will endure.