Can You Run a Furnace With a Cracked Heat Exchanger?

Don’t jeopardize your home and safety with a damaged heat exchanger. Call JC Mechanical today for help!

Furnace maintenance ensures your household has adequate heat for Colorado’s chilly winters. Still, it’s quite common for homeowners not to know everything about complex heating systems, even if they know the importance of components like heat exchangers. For example, people often ask, “Can you run a furnace with a cracked heat exchanger?”

As one of the top furnace repair contractors in Centennial, CO, and the surrounding communities, the expert HVAC technicians at JC Mechanical have years of experience providing comprehensive furnace services to our customers. Below, we share details about heat exchangers in furnaces and whether you can safely operate your heating system with a damaged heating element. 

can you run a furnace with a cracked heat exchanger

What’s the Purpose of a Furnace Heat Exchanger?

gas furnace uses a heat exchanger to warm air through combustion. The component consists of hollow metal coils that contain flue gases that develop when the furnace initiates combustion.

The coils absorb the heat as the hot flue gases like sulfur dioxide, nitrous oxide, and carbon monoxide travel through the heat exchanger. A blower fan blows air over the coils and sends the heated air to every room in the house via air ducts. Without a functioning heat exchanger, a gas furnace can’t generate warm air for the home. 

Will Your Furnace Work With a Broken Heat Exchanger?

Can you run a furnace with a cracked heat exchanger? Technically, you can, but you shouldn’t. Heat exchangers contain the dangerous gases that form from the combustion process. Even if the heat exchanger has a hairline crack, that’s enough damage to warrant a call to a qualified HVAC company to address a potential gas leak. 

How do heat exchangers crack? In most cases, the heat exchanger sustains damage due to the furnace overheating. 

When you run your gas furnace constantly, it can be hard for the system to generate enough airflow to absorb and transfer the heat that the component generates effectively. The lack of airflow will cause it to overheat and continuously expand and contract from the excessive heat. It’s usually common for the weakest parts of the heat exchanger to fracture when furnace overheating is a problem. 

Another way for a heat exchanger to crack is improper installation. If you hire an unqualified or inexperienced HVAC technician to replace a heat exchanger, they could unintentionally damage the part during the process. It’s crucial to always hire a professional company to handle essential part replacements in gas furnaces due to the potential hazards that could arise from inexperience or carelessness. 

Potential Dangers of a Damaged Heat Exchanger

Though you could continue running your furnace with a broken or cracked heat exchanger, it’s best to shut the gas furnace off as soon as you suspect a problem. Here’s why. 

Gas Leaks

The biggest risk of running a gas furnace with a heat exchanger crack is a gas leak, specifically carbon monoxide. Carbon monoxide is a byproduct of burning natural gas or propane. Yet, it’s a colorless and odorless gas that most people don’t realize is leaking into their homes until someone gets sick or a carbon monoxide detector goes off. 

A carbon monoxide leak anywhere in your home is cause for immediate concern because it’s incredibly dangerous. A fully functioning furnace contains the harmful gaseous byproducts inside the heat exchanger before transporting them through a flue pipe that vents outside of the house. If the heat exchanger cracks, the toxic gases will seep into the home through the furnace. This leak puts the household at risk for serious illness and possibly death.

Common symptoms of carbon monoxide exposure include:

  • Headache
  • Drowsiness
  • Weakness
  • Nausea or vomiting
  • Confusion
  • Shortness of breath

Furnace Shut-Off

Though carbon monoxide leaks are the most dangerous consequences of running a gas furnace with a cracked exchanger, they aren’t the only ones. You could also have an inefficient heating unit on your hands. 

Some modern gas furnaces have safety features that detect potential hazards with the system. When something triggers the feature, the furnace will shut down to prevent the hazard. For example, a heating system with a flame sensor will shut off if the sensor doesn’t detect a strong enough flame to initiate a complete combustion. 

Unfortunately, there aren’t any sensors that detect a crack in a heat exchanger. However, some models have safety switches that detect a change in pressure inside the furnace. If there isn’t enough pressure to move gas byproducts safely through the flue pipe, the switch will flip and turn off the furnace. When something triggers this sensor, the blower fan stops working, which will cause the furnace to shut down. 

Steps To Take if Your Heat Exchanger Cracks

Despite “Yes” being the answer to, “Can you run a furnace with a cracked heat exchanger?” you want to take these steps if you think your furnace is experiencing this problem:

  • Turn the Furnace Off: Don’t continue letting your furnace run if you think it has any problem that could result in a gas leak. 
  • Call a Professional: Immediately call an HVAC technician to inspect your furnace. If the heat exchanger is bad, they can replace it. 
  • Install Carbon Monoxide Detectors: Put carbon monoxide detectors on each floor of your home to warn you of a potential leak before the problem worsens enough to cause sickness.
  • Schedule Routine Furnace Maintenance: Regular maintenance includes heat exchanger inspections. 

Turn to JC Mechanical for Reliable Furnace Repair

If your central heating is not working due to a cracked heat exchanger or another faulty furnace part, you can rely on our JC Mechanical professionals to take care of your unit. We’re a top-rated HVAC company serving Centennial, Colorado, and we offer 24-hour emergency furnace repair to ensure the comfort and safety of our customers. Our certified technicians specialize in providing professional services and reliable HVAC solutions. 

Instead of asking, “Can you run a furnace with a cracked heat exchanger?” let JC Mechanical keep your entire heating system in great condition. Call us today at (720) 779-7263 to request an appointment. 

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