Can Furnaces Catch Fire?

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

As reported by the National Fire Protection Association (NFPA), heating systems like furnaces are a leading cause of home fires, causing almost 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage every year. 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. Find out more about the most likely causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Aging furnaces are more susceptible to safety concerns since they may be designed differently and slide 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. 

Overheated Motor

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

• A clogged filter can impede airflow and force the motor to work longer. Sooner or later, the motor might overheat, increasing the risk of fire. 
• Dirt can accumulate around and coat the motor, forcing it to retain heat, which can cause a fire. 
• Exposed or corroded wiring can cause the voltage to elevate, increasing the chances of an electrical fire. 
• Exceedingly tight or damaged motor bearings can heat up whenever the furnace runs. Without the proper lubrication, the bearings may eventually light on fire. 

Blocked Furnace Flue 

Yard debris, animal nests and other obstructions can block the furnace flue, restricting oxygen. This leads to soot buildup and bad ventilation, decreasing efficiency and increasing 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 persists, your heating equipment could be badly 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 produced by your furnace is exchanged to the air circulating through your home. A heat exchanger clogged with soot or corrosion has the same impact as a blocked furnace flue—reduced performance and a higher risk of flame rollout. 

Cracked Heat Exchanger 

Various problems can take place if corrosion breaks the heat exchanger. First, it reduces suction in this chamber, leading to less airflow and increased flame rollout. Second, it emits fumes, including carbon monoxide, into your home. Inhaling 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 present. 

Inadequate Gas Pressure 

Furnaces need a precise combination of natural gas and air to create 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 within the heat exchanger, increasing the rate of corrosion. 

Conversely, high gas pressure can produce excessive heat in 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 light on fire, here are the steps you can take to avoid furnace fires: 

• Change the air filter regularly: Check the filter each month and change it when it appears dirty or every three months, whichever comes first. 
• Keep an eye on the furnace flue: Inspect the exterior vent for obstructions and take care of any you find. 
• Don’t place combustible items close to the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept at a minimum 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 promptly 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, prioritize 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 reason, Service Experts Heating, Air Conditioning & Plumbing is here for you. Our HVAC pros can inspect, clean and test the system to ensure safe operation. If anything seems off, we’ll recommend a repair or a modification, giving 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.