A furnace is often a background player for your home, keeping you warm during the cold winter months. It often won't be noticed until something breaks down. 

One root cause could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to learn the evidence of a cracked heat exchanger and what to 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 moves throughout the system. It typically does this through coils or tubes that heat up the air while functioning 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? 

Because of its important role, it shouldn't come as a surprise that a cracked heat exchanger can pose a risk. A damaged heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed across your home. 

For this reason, never run your furnace if you think there's a crack in the heat exchanger, as this could make your entire family ill. Call an HVAC professional as soon as possible if you think your heater has a cracked heat exchanger that should be repaired. 

Four Symptoms of a Cracked Heat Exchanger: 

  • Furnace turns off: Cracks in the heat exchanger could cause your furnace to switch off. 
  • Strange Smells: If the air leaving your furnace has a powerful chemical scent, it could be evidence gas is seeping 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 poisoning symptoms: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm could go off or family members might start experiencing signs of carbon monoxide poisoning. Complications include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel unwell, get out of 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 Should Do if Your Furnace Heat Exchanger is Cracked 

If you worry your furnace has a cracked heat exchanger, contact a professional with extensive experience in furnace installation McKinney and Frisco as soon as possible so they can examine your system and, if needed, start a furnace heat exchanger replacement. Costs should differ 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 often included in the warranty. You should check the warranty paperwork on your furnace, as while the warranty might not cover the entire cost of repairs, it can significantly reduce your bill.  

How to Prevent a Cracked Heat Exchanger in Your Home  

One of the easiest ways to minimize the risk of problems in your furnace overall is with regular furnace maintenance. Furnaces provide the best possible return on investment when they run efficiently. Calling a trained professional to inspect your furnace for broken-down parts, clogs in the air filters and other potential problems can help you avoid getting a big bill later on.  

It’s also a good idea to review your furnace filters every few months – it’s ideal 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 drawing air through a clogged filter makes your entire furnace work longer to accomplish its job. And the harder your furnace works, the more wear and tear pieces like the heat exchanger will sustain.