Can Furnaces Catch Fire?

The return of cold temperatures increases your dependence on home heating equipment in the fall. If your furnace isn’t functioning properly, it might 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 leading source of home fires, contributing to almost 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage annually. Space heaters and fireplaces generate most of the fires involving heating equipment, but central heaters, including furnaces, are responsible for about 12% of these blazes. Find out more about the most likely causes of furnace fires and how to prevent them. 

Causes of Furnace Fires

Old furnaces are more vulnerable to safety concerns since they might be designed differently and slide into disrepair through the years. Nevertheless, 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 different ways. Here are the main risks:  

• A clogged filter can impede airflow and cause the motor to work longer. Sooner or later, the motor might overheat, elevating the risk of fire. 
• Dirt can accumulate around and insulate the motor, forcing it to hold heat, which can trigger a fire. 
• Exposed or corroded wiring can cause the voltage to increase too much, increasing the risk of an electrical fire. 
• Excessively tight or damaged motor bearings can heat up as the furnace is on. Without the proper lubrication, the bearings may eventually catch fire. 

Clogged Furnace Flue 

Yard debris, animal nests and other obstructions can clog the furnace flue, lowering oxygen. This leads to soot accumulation and weaker ventilation, lowering efficiency and raising the risk of flame rollout. Flame rollout is when fire reaches past the heat exchanger and burns the parts within your furnace. If this problem continues, your heating equipment may be badly damaged, and the fire may even spread to areas outside the furnace. 

Clogged Heat Exchanger 

The heat exchanger is a sealed combustion chamber where the heat created by your furnace is exchanged to the air circulating throughout your home. A heat exchanger clogged 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 

Several problems can happen if corrosion cracks the heat exchanger. First, it reduces suction in this chamber, leading to less airflow and increased flame rollout. Second, it produces fumes, such as carbon monoxide, into your home. Breathing CO gas can be fatal, so never ignore 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 depend on an accurate combination of natural gas and air to ensure 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 leads to unwanted condensation inside the heat exchanger, increasing the rate of corrosion. 

Conversely, high gas pressure can lead to excessive heat inside 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 light on fire, here are the steps you can take to prevent furnace fires: 

• Replace the air filter regularly: 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 clear out any you find. 
• Don’t place combustible items around 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. 
• Put in 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 right away to diagnose and repair the problem before it results in a furnace fire. 

• Schedule yearly furnace maintenance: It isn’t always easy to recognize 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 yearly tune-up? Do you need help resolving a problem with your furnace? Whatever the case, Bryant Heating & Cooling Service Experts is here for you. Our HVAC pros 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, 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 Bryant Heating & Cooling Service Experts office today.