Can Furnaces Catch Fire?

The return of cold temperatures boosts your dependence on home heating equipment each fall. If your furnace isn’t functioning correctly, it might develop into a fire hazard and endanger your family’s safety. 

As reported by the National Fire Protection Association (NFPA), heating equipment is a major cause of home fires, leading to approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage every year. Space heaters and fireplaces generate most of the fires concerning heating equipment, but central heaters, like furnaces, are liable for just about 12% of these blazes. Learn the most likely causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Old furnaces are more susceptible to safety concerns because they could be manufactured differently and fall 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. 

Overheating Motor

A furnace motor can overheat in several ways. Here are the main risks:  

• A clogged filter can impede airflow and force the motor to work longer. Eventually, the motor may overheat, elevating the risk of fire. 
• Dirt can accumulate around and cover up the motor, forcing it to absorb heat, which can cause a fire. 
• Exposed or damaged wiring can cause the voltage to get too high, increasing the chances of an electrical fire. 
• Excessively tight or damaged motor bearings can heat up as the furnace starts. Without the proper lubrication, the bearings may eventually catch fire. 

Obstructed Furnace Flue 

Yard debris, animal nests and other obstructions can block the furnace flue, reducing oxygen. This leads to soot buildup and weaker ventilation, lowering efficiency and increasing the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts in your furnace. If this problem continues, your heating equipment can be seriously 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 throughout your home. A heat exchanger blocked with soot or corrosion has the same effect as a blocked furnace flue—reduced performance and a higher risk of flame rollout. 

Cracked Heat Exchanger 

Several problems can happen if corrosion cracks the heat exchanger. First, it reduces suction in this chamber, resulting in less airflow and increased flame rollout. Second, it releases fumes, including carbon monoxide, into your home. Inhaling CO gas can be lethal, so never neglect your carbon monoxide alarms. CO gas can also return to the source of the leak and ignite if a flame is lit. 

Inadequate Gas Pressure 

Furnaces require an exact 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 produces unwanted condensation within 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 ignite. Such fires can easily spread to other areas. 

How to Prevent Furnace Fires 

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

• Change the air filter consistently: Check the filter once a month and change it when it appears dirty or every three months, whichever comes first. 
• Check the furnace flue: Periodically check the exterior vent for obstructions and remove any you find. 
• Don’t place combustible items around the furnace: Things including cardboard boxes, paper, clothing and other combustibles should be kept more than 3 feet away from the furnace and any other heating equipment. 
• Put in a flame rollout switch: This safety component 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 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 taking care of a problem with your furnace? Whatever the case, Service Experts Heating, Air Conditioning & Plumbing 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 suggest 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.