Can Furnaces Catch Fire?

The return of cold temperatures increases your dependence on home heating equipment every fall. If your furnace isn’t working properly, it might develop into a fire hazard and endanger your family’s safety. 

As stated by the National Fire Protection Association (NFPA), heating systems are a top factor of home fires, contributing to nearly 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 affecting heating equipment, but central heaters, like furnaces, are liable for around 12% of these blazes. Learn more about the most likely causes of furnace fires and how to prevent them. 

Causes of Furnace Fires

Older furnaces are more exposed to safety problems because they might be configured differently and settle into disrepair through the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should be aware of these causes of furnace fires. 

Overheating Motor

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

• A clogged filter can impede airflow and force the motor to work longer. Sooner or later, the motor may overheat, increasing the risk of fire. 
• Dirt can collect around and cover up the motor, forcing it to hold 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 damaged motor bearings can heat up whenever the furnace is on. Without adequate lubrication, the bearings may eventually light on fire. 

Clogged Furnace Flue 

Yard debris, animal nests and other obstructions can obstruct the furnace flue, reducing oxygen. This results in soot buildup and weaker 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 badly damaged, and the fire can spread to areas outside the furnace. 

Clogged Heat Exchanger 

The heat exchanger is a restricted combustion chamber where the heat generated by your furnace transfers 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 an increased risk of flame rollout. 

Cracked Heat Exchanger 

Numerous problems can happen if corrosion damages the heat exchanger. First, it lowers suction in this chamber, triggering less airflow and increased flame rollout. Second, it produces fumes, such as carbon monoxide, into your home. Breathing CO gas can be deadly, 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. 

Improper Gas Pressure 

Furnaces need a precise 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 inside the heat exchanger, accelerating 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 ignite. Such fires can readily spread to other areas. 

How to Prevent Furnace Fires 

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

• Replace the air filter on a regular basis: 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 remove any you find. 
• Don’t keep combustible items around the furnace: Things like 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 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 right away to diagnose and repair the problem before it produces a furnace fire. 

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

Schedule Furnace Services Today 

Is it time for your annual tune-up? Do you need help resolving a problem with your furnace? Whatever the case, 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 perform a repair or a modification, offering 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.