Can Furnaces Catch Fire?

The return of cold temperatures increases your reliance on home heating equipment each fall. If your furnace isn’t operating correctly, it could grow to be a fire hazard and threaten your family’s safety. 

According to the National Fire Protection Association (NFPA), heating equipment is a top cause of home fires, causing nearly 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage every year. Space heaters and fireplaces cause the majority of fires involving heating equipment, but central heaters, including furnaces, are responsible for around 12% of these blazes. Learn the primary causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Old furnaces are more vulnerable to safety hazards as they could be designed differently and slide into disrepair over the years. Still, whether your furnace is more than a decade old or brand new, you should be aware of these causes of furnace fires. 

Overheated Motor

A furnace motor can overheat in various ways. Here are the biggest risks:  

• A clogged filter can restrict airflow and cause the motor to work more. Eventually, the motor may overheat, raising the risk of fire. 
• Dirt can collect around and coat the motor, forcing it to retain heat, which can cause a fire. 
• Exposed or corroded wiring can cause the voltage to get too high, increasing the chances of an electrical fire. 
• Excessively tight or worn motor bearings can heat up when the furnace starts. Without adequate lubrication, the bearings may eventually catch fire. 

Blocked Furnace Flue 

Yard debris, animal nests and other obstructions can clog the furnace flue, restricting oxygen. This leads to soot buildup and improper ventilation, lowering efficiency and increasing the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts inside your furnace. If this problem persists, your heating equipment may be severely damaged, and the fire could spread to areas outside the furnace. 

Clogged Heat Exchanger 

The heat exchanger is a closed combustion chamber where the heat produced by your furnace is exchanged to the air circulating throughout your home. A heat exchanger clogged with soot or corrosion has the same effect as a blocked furnace flue—reduced performance and an increased risk of flame rollout. 

Cracked Heat Exchanger 

Various problems occur if corrosion breaks the heat exchanger. First, it reduces suction inside this chamber, resulting in less airflow and increased flame rollout. Second, it emits fumes, like carbon monoxide, into your home. Inhaling CO gas can be lethal, so never ignore your carbon monoxide alarms. CO gas can also flash back to the source of the leak and ignite if a flame is present. 

Improper Gas Pressure 

Furnaces depend on a precise combination of natural gas and air to generate safe and efficient combustion. Too little pressure is often the result of clogged burner orifices. This problem makes the burner flames more likely to roll out. It also causes unwanted condensation inside the heat exchanger, accelerating the rate of corrosion. 

On the other hand, high gas pressure can create excessive heat inside the furnace, which can cause the soot inside the heat exchanger to combust. Such fires can quickly spread to other areas. 

How to Prevent Furnace Fires 

Based on the different ways a furnace can catch fire, here are the steps you can take to prevent furnace fires: 

• Change the air filter regularly: Check the filter monthly and change it when it appears dirty or every three months, whichever comes first. 
• Check the furnace flue: Inspect the exterior vent for obstructions and clear out any you find. 
• Don’t store combustible items near the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept at least 3 feet away from the furnace and all other heating equipment. 
• Put in a flame rollout switch: This safety device detects if a fire or hot exhaust gases are inside your furnace’s burner compartment. If the rollout switch trips, have your furnace inspected right away to diagnose and repair the problem before it produces a furnace fire. 

• Schedule annual furnace maintenance: It isn’t always easy to tell if your furnace is operating unsafely. Whether you notice warning signs or not, remember furnace maintenance every fall. 

Schedule Furnace Services Today 

Is it time for your yearly tune-up? Do you need help fixing a problem with your furnace? Whatever the case, Midland Air Service Experts is here for you. Our HVAC experts can inspect, clean and test the system to ensure safe operation. If anything looks out of place, we’ll recommend a repair or a modification, providing you peace of mind that your furnace is unlikely to catch fire. For more details or to schedule furnace maintenance, please contact your local Midland Air Service Experts office today.