Can Furnaces Catch Fire?

The return of cold temperatures raises your dependence on home heating equipment every fall. If your furnace isn’t functioning correctly, it may grow to be a fire hazard and jeopardize your family’s safety. 

As reported by the National Fire Protection Association (NFPA), heating systems like furnaces are a leading source of home fires, causing almost 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage every year. Space heaters and fireplaces cause most of the 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 prevent them. 

Causes of Furnace Fires

Aging furnaces are more exposed to safety hazards because they might be manufactured differently and settle into disrepair over the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should know about these causes of furnace fires. 

Overheated Motor

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

• A clogged filter can restrict airflow and force the motor to work harder. At some point, the motor might overheat, increasing the risk of fire. 
• Dirt can gather around and coat the motor, forcing it to retain heat, which can cause a fire. 
• Exposed or corroded wiring can cause the voltage to increase too much, increasing the risk of an electrical fire. 
• Overly tight or worn motor bearings can heat up when the furnace is on. Without the proper lubrication, the bearings could eventually catch fire. 

Blocked Furnace Flue 

Yard debris, animal nests and other materials can obstruct the furnace flue, restricting oxygen. This leads to soot building up and bad ventilation, lowering efficiency and increasing the risk of flame rollout. Flame rollout is when fire gets out of the heat exchanger and burns the parts in your furnace. If this problem remains, your heating equipment could be severely damaged, and the fire can spread to areas outside the furnace. 

Obstructed Heat Exchanger 

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

Cracked Heat Exchanger 

Various problems can happen if corrosion cracks the heat exchanger. First, it lowers suction in this chamber, triggering less airflow and increased flame rollout. Second, it emits fumes, including carbon monoxide, into your home. Breathing in CO gas can be fatal, so never dismiss your carbon monoxide alarms. CO gas can also flash back to the source of the leak and ignite if a flame is present. 

Inadequate Gas Pressure 

Furnaces require an accurate combination of natural gas and air to produce safe and efficient combustion. Too little pressure is often because of clogged burner orifices. This problem makes the burner flames more likely to roll out. It also leads to unwanted condensation in the heat exchanger, increasing the rate of corrosion. 

Conversely, high gas pressure can create excessive heat inside the furnace, which can cause the soot inside the heat exchanger to ignite. Such fires can readily spread to other areas. 

How to Prevent Furnace Fires 

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

• Replace the air filter consistently: Check the filter monthly and change it when it looks dirty or every three months, whichever comes first. 
• Check the furnace flue: Examine the exterior vent for obstructions and clear out any you find. 
• Don’t store combustible items around the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept more than 3 feet away from the furnace and all other heating equipment. 
• Install 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 triggers, have your furnace inspected as soon as possible to diagnose and repair the problem before it produces a furnace fire. 

• Request annual furnace maintenance: It isn’t always easy to notice if your furnace is working unsafely. Whether you notice warning signs or not, prioritize 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 reason, Service Experts Heating, Air Conditioning & Plumbing is here for you. Our HVAC experts can inspect, clean and test the system to provide safe operation. If anything doesn’t seem right, we’ll recommend a repair or a modification, providing you peace of mind that your furnace is unlikely to catch fire. For more info or to schedule furnace maintenance, please contact your local Service Experts Heating, Air Conditioning & Plumbing office today.