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

One root cause could be that your furnace has a cracked heat exchanger. It can potentially be hazardous, so it’s important to familiarize yourself with 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 transfers heat from the combustion chamber of your furnace to the air that circulates throughout the ventilation. It generally handles this via coils or tubes that warm the air while serving as a barrier to keep gas created in the combustion chamber, called flue gasses, from getting out into your home.  

Is a Cracked Heat Exchanger Dangerous? 

Given its central role, it’s no surprise that a damaged heat exchanger can be hazardous. A crack in the heat exchanger can allow dangerous gasses – such as carbon monoxide, which can be lethal – to flow throughout your home. 

For obvious reasons, do NOT turn on your heating if you think it has a cracked heat exchanger, as doing so could make your entire family ill. Call an HVAC professional as soon as possible if you think your heating has a cracked heat exchanger that should be repaired. 

Four Signs of a Cracked Heat Exchanger: 

  • Furnace shuts off: A crack in your heat exchanger could cause your furnace to shut off. 
  • Strange Smells: If the air leaving your furnace has an intense chemical smell, it could be evidence gasses are seeping through cracks in your heat exchanger. These byproducts, which can smell like formaldehyde, are a significant warning sign. 
  • Carbon monoxide alarm is triggered or you feel symptoms of poisoning: If a cracked heat exchanger is releasing carbon monoxide inside your home, your carbon monoxide alarm may go off or family members may struggle with signs of carbon monoxide poisoning. Side effects include headaches, dizziness, weakness, nausea, vomiting or feeling sleepy. If your alarm goes off or you feel sick, exit the home right away and then call for help. 
  • Soot: If you find black sooty buildup around the exterior of your furnace, it’s another sign something might be seriously wrong.

What You Should Do if the Furnace Heat Exchanger is Cracked 

If you suspect your furnace has a cracked heat exchanger, call a pro with extensive experience in furnace installation Huntingburg as soon as possible so they can take a look at your system and, if required, start a furnace heat exchanger replacement. Costs will fluctuate depending on the situation, but estimates run in the neighborhood of $1,000 to $3,000. 

However, the good news is that heat exchangers are regularly included in the warranty. You’ll want to check the warranty paperwork on your furnace, because while the warranty may 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 minimize the risk of problems in your furnace overall is via regular furnace maintenance. Furnaces work the best when they run efficiently. Calling a skilled professional to examine your furnace for worn-out parts, clogs in the air filters and other likely problems can keep you from getting a big bill later on.  

It’s also beneficial to take a look at your furnace filters every few months – it’s ideal some filters be replaced 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 more vigorously to do its job. And the harder your furnace has to work, the more strain parts like the heat exchanger will sustain.