Can Furnaces Catch Fire?

The return of cooler temperatures boosts your dependency on home heating equipment every fall. If your furnace isn’t operating properly, it could become a fire hazard and endanger your family’s safety. 

According to the National Fire Protection Association (NFPA), heating systems are a leading source of home fires, causing almost 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage each year. Space heaters and fireplaces generate most of the fires involving heating equipment, but central heaters, like furnaces, are accountable for just about 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 problems since they may be manufactured differently and slide into disrepair over the years. Still, 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 most common risks:  

• A clogged filter can block airflow and cause the motor to work longer. Eventually, the motor may overheat, elevating the risk of fire. 
• Dirt can gather around and coat the motor, forcing it to absorb heat, which can cause a fire. 
• Exposed or corroded wiring can cause the voltage to increase too much, increasing the chances of an electrical fire. 
• Excessively tight or damaged motor bearings can heat up whenever the furnace is on. Without the appropriate lubrication, the bearings may eventually catch fire. 

Clogged Furnace Flue 

Yard waste, animal nests and other materials can block the furnace flue, lowering oxygen. This causes soot buildup and bad ventilation, limiting efficiency and increasing the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts in your furnace. If this problem persists, your heating equipment can be badly damaged, and the fire could spread to areas outside the furnace. 

Clogged 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 impact as a blocked furnace flue—reduced performance and an increased risk of flame rollout. 

Cracked Heat Exchanger 

Various problems can take place if corrosion damages 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. 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. 

Improper Gas Pressure 

Furnaces need an exact mixture 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 produces unwanted condensation in the heat exchanger, increasing the rate of corrosion. 

On the other hand, high gas pressure can create excessive heat within the furnace, which can cause the soot inside the heat exchanger to burn. Such fires can quickly spread to other areas. 

How to Prevent Furnace Fires 

Based on the listed 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 each month 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 clear out any you find. 
• Don’t store combustible items around the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept at least 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 as soon as possible to diagnose and repair the problem before it produces a furnace fire. 

• Schedule yearly furnace maintenance: It isn’t always easy to tell 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 taking care of a problem with your furnace? Whatever is happening, Service Experts Heating, Air Conditioning & Plumbing is here for you. Our HVAC experts can inspect, clean and test the system to provide safe operation. If anything looks out of place, 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.