A furnace is often a background player at home, helping keep you warm across the cold winter months. It often doesn’t get noticed until something breaks down. 

One source may be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s worthwhile to familiarize yourself with the evidence 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 transfers heat from the combustion chamber inside your furnace to the air that flows inside the air ducts. It usually handles this via coils or tubes that warm the air while functioning as a barrier to keep byproducts created in the combustion chamber, called flue gasses, from getting out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Because of its central role, it shouldn't come as a surprise that a damaged heat exchanger can be very dangerous. A damaged heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to flow across your home. 

For obvious reasons, don't ever use your heating if you believe it has a cracked heat exchanger, as this could make the whole family sick. Call an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that needs to be repaired. 

Four Warning Signs of a Cracked Heat Exchanger: 

  • Furnace switches off: A crack in your heat exchanger may cause your furnace to switch off. 
  • Unusual Smells: If the air leaving your furnace has a powerful chemical scent, it might be evidence gasses are slipping through cracks in your heat exchanger. These byproducts, which will often smell like formaldehyde, are a common warning sign. 
  • Carbon monoxide alarm initiates or you feel poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide into your home, your carbon monoxide alarm may go off or household members might start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If an alarm goes off or you feel unwell, exit the home as soon as you can and then call for help. 
  • Soot: If you notice black sooty buildup around the exterior of your furnace, it’s an indication something may be seriously wrong.

What You Should Do if Your Furnace Heat Exchanger is Cracked 

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

However, the good news is that heat exchangers are generally protected by the warranty. You’ll want to confirm the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it can significantly shrink 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 through regular furnace maintenance. Furnaces offer the most benefits when they run efficiently. Contacting a certified professional to examine your furnace for old parts, dirty filters and other potential 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 changed 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 the entire furnace work more vigorously to do its job. And the harder your furnace has to work, the more wear and tear pieces like the heat exchanger will experience.