Can Furnaces Catch Fire?

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

As reported by the National Fire Protection Association (NFPA), heating equipment is a top cause of home fires, causing approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage each year. Space heaters and fireplaces cause most of the fires affecting heating equipment, but central heaters, such as furnaces, are liable for around 12% of these blazes. Learn more about the primary causes of furnace fires and how to minimize them. 

Causes of Furnace Fires

Aging furnaces are more susceptible to safety concerns because they might be configured differently and slide into disrepair through the years. Still, whether your furnace is more than a decade old or brand new, you should be familiar with these causes of furnace fires. 

An Overheated Motor

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

• A clogged filter can restrict airflow and cause the motor to work longer. At some point, the motor can overheat, increasing the risk of fire. 
• Dirt can gather around and coat the motor, forcing it to retain heat, which can lead to a fire. 
• Exposed or corroded wiring can cause the voltage to increase too much, increasing the chances of an electrical fire. 
• Exceedingly tight or worn motor bearings can heat up whenever the furnace starts. Without the appropriate lubrication, the bearings may eventually light on fire. 

Clogged Furnace Flue 

Yard debris, animal nests and other materials can block the furnace flue, restricting oxygen. This leads to soot accumulation and bad ventilation, decreasing efficiency and raising the risk of flame rollout. Flame rollout is when fire gets out of the heat exchanger and burns the parts inside your furnace. If this problem remains, 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 restricted combustion chamber where the heat generated by your furnace is moved to the air circulating within your home. A heat exchanger clogged up with soot or corrosion has the same result as a blocked furnace flue—reduced performance and an increased risk of flame rollout. 

Cracked Heat Exchanger 

Several problems can happen if corrosion breaks the heat exchanger. First, it lowers suction within this chamber, leading to less airflow and increased flame rollout. Second, it emits fumes, such as carbon monoxide, into your home. Breathing CO gas can be fatal, so never dismiss your carbon monoxide alarms. CO gas can also return to the source of the leak and ignite if a flame is found. 

Improper Gas Pressure 

Furnaces require a precise mixture of natural gas and air to create 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 produces unwanted condensation in the heat exchanger, increasing the rate of corrosion. 

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

How to Prevent Furnace Fires 

Based on the different ways a furnace can combust, here are the steps you can take to avoid furnace fires: 

• Change the air filter on a regular basis: 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 remove any you find. 
• Don’t keep 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 all other heating equipment. 
• Add 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 results in a furnace fire. 

• Request yearly furnace maintenance: It isn’t always easy to tell 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 resolving a problem with your furnace? Whatever the reason, Service Experts Heating, Air Conditioning & Plumbing is here for you. Our HVAC professionals can inspect, clean and test the system to ensure safe operation. If anything doesn’t seem right, we’ll suggest a repair or a modification, offering you peace of mind that your furnace is unlikely to catch fire. For more information or to schedule furnace maintenance, please contact your local Service Experts Heating, Air Conditioning & Plumbing office today.