Can Furnaces Catch Fire?

The return of low temperatures increases your dependency on home heating equipment each fall. If your furnace isn’t operating properly, it may develop into a fire hazard and endanger your family’s safety. 

According to the National Fire Protection Association (NFPA), heating systems like furnaces are a major source of home fires, leading to approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage annually. Space heaters and fireplaces cause most of the fires involving heating equipment, but central heaters, including furnaces, are responsible for just about 12% of these blazes. Learn more about the most likely causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Old furnaces are more susceptible to safety hazards since they may be manufactured differently and slide into disrepair through the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should know about these causes of furnace fires. 

An Overheated 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 harder. Sooner or later, the motor might overheat, increasing the risk of fire. 
• Dirt can accumulate around and cover up the motor, forcing it to absorb heat, which can lead to a fire. 
• Exposed or damaged wiring can cause the voltage to get too high, increasing the risk of an electrical fire. 
• Exceedingly tight or worn motor bearings can heat up whenever the furnace runs. Without the appropriate lubrication, the bearings can eventually light on fire. 

Obstructed Furnace Flue 

Yard waste, animal nests and other materials can clog the furnace flue, lowering oxygen. This causes soot building up and bad ventilation, lowering efficiency and raising the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts in your furnace. If this problem remains, your heating equipment may 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 created by your furnace is moved to the air circulating within 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 

Numerous problems can take place if corrosion breaks the heat exchanger. First, it affects suction in this chamber, triggering less airflow and increased flame rollout. Second, it produces fumes, including carbon monoxide, into your home. Inhaling CO gas can be fatal, 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 accurate mixture 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 causes unwanted condensation in the heat exchanger, increasing the rate of corrosion. 

On the other hand, high gas pressure can produce excessive heat within the furnace, which can cause the soot inside the heat exchanger to combust. Such fires can readily 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 prevent furnace fires: 

• Replace the air filter consistently: Check the filter each month and change it when it seems dirty or every three months, whichever comes first. 
• Keep an eye on the furnace flue: Examine the exterior vent for obstructions and remove any you find. 
• Don’t store combustible items close to the furnace: Things including cardboard boxes, paper, clothing and other combustibles should be kept at least 3 feet away from the furnace and all other heating equipment. 
• Install a flame rollout switch: This safety system detects if a fire or hot exhaust gases are inside your furnace’s burner compartment. If the rollout switch triggers, have your furnace inspected promptly to diagnose and repair the problem before it causes a furnace fire. 

• Request yearly furnace maintenance: It isn’t always easy to notice if your furnace is performing unsafely. Whether you notice warning signs or not, prioritize furnace maintenance every fall. 

Schedule Furnace Services Today 

Is it time for your annual tune-up? Do you need help fixing 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 details or to schedule furnace maintenance, please contact your local Service Experts Heating, Air Conditioning & Plumbing office today.