A furnace is almost always a background player at home, keeping you warm across the cold winter months. It often won't be noticed until something breaks down. 

One root cause may be that your furnace has a cracked heat exchanger. It’s a potentially dangerous issue, so it’s critical to know the symptoms of a cracked heat exchanger and what to do if you suspect 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 ventilation. It usually does this with coils or tubes that warm the air while serving as a barrier to keep gas formed in the combustion chamber, called flue gasses, from escaping out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Thanks to its central role, it’s no surprise that a cracked heat exchanger can be hazardous. Cracks in the heat exchanger can permit dangerous gasses – such as carbon monoxide, which can be lethal – to be distributed throughout your home. 

For that reason, do NOT run your heating if you believe there's a crack in the heat exchanger, as letting it run could make the whole family sick. Call an HVAC professional as soon as possible if you are worried your heating has a cracked heat exchanger that needs repair. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace switches off: Cracks in the heat exchanger could cause your furnace to switch off. 
  • Strange Smells: If the air coming out of your furnace has a strong chemical odor, it may be an indicator that gasses are leaking through cracks in your heat exchanger. These gasses, which may smell like formaldehyde, are a major warning sign. 
  • Carbon monoxide alarm goes off or you feel symptoms of poisoning: If a cracked heat exchanger is emitting carbon monoxide inside your home, your carbon monoxide alarm should go off or household members might struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling drowsy. If the alarm goes off or you feel unwell, get out of the home right away and then call for help. 
  • Soot: If you spot black sooty buildup near the exterior of your furnace, it’s an indication something may be seriously wrong.

What to Do if the Furnace Heat Exchanger is Cracked 

If you worry your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation Muskogee as soon as possible so they can inspect your system and, if necessary, start a furnace heat exchanger replacement. Costs should fluctuate depending on the situation, but estimates can roughly suggest $1,000 to $3,000. 

Estimates aside, the good news is that heat exchangers are often protected by the warranty. You should confirm the warranty paperwork on your furnace, since while the warranty might not cover the entire cost of repairs, it could significantly lower 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 via routine furnace maintenance. Furnaces offer the most benefits when they operate efficiently. Hiring a skilled professional to inspect your furnace for worn-out parts, dirty filters and other common problems can keep you from getting a big bill later on.  

It’s also beneficial to review your furnace filters every few months – it’s encouraged some filters be swapped out every 90 days or sooner if they are dirty or grimy. While the filters aren't connected to 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 deterioration pieces like the heat exchanger will sustain.