Can Furnaces Catch Fire?

The return of cold temperatures raises your dependency on home heating equipment every fall. If your furnace isn’t working correctly, it may become a fire hazard and jeopardize your family’s safety. 

According to the National Fire Protection Association (NFPA), heating equipment is a leading cause of home fires, leading to approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage every year. Space heaters and fireplaces start most of the fires concerning heating equipment, but central heaters, including furnaces, are responsible for about 12% of these blazes. Learn the leading causes of furnace fires and how to minimize them. 

Causes of Furnace Fires

Older furnaces are more exposed to safety hazards since they might be designed differently and fall into disrepair through the years. Still, whether your furnace is more than a decade old or brand new, you should be aware of 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 restrict airflow and force the motor to work more. At some point, the motor might overheat, increasing the risk of fire. 
• Dirt can gather around and insulate the motor, forcing it to absorb heat, which can lead to a fire. 
• Exposed or damaged 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 the appropriate lubrication, the bearings can eventually catch fire. 

Clogged Furnace Flue 

Yard waste, animal nests and other materials can block the furnace flue, reducing oxygen. This leads to soot accumulation and weaker ventilation, lowering efficiency and raising the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts within your furnace. If this problem continues, your heating equipment may be severely damaged, and the fire could spread to areas outside the furnace. 

Obstructed Heat Exchanger 

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

Various problems can take place if corrosion breaks the heat exchanger. First, it affects suction in this chamber, triggering less airflow and increased flame rollout. Second, it produces fumes, such as carbon monoxide, into your home. Breathing in 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 depend on an exact 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, 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 quickly spread to other areas. 

How to Prevent Furnace Fires 

Based on the different ways a furnace can catch fire, here are the steps you can take to avoid 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. 
• 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 around the furnace: Things like cardboard boxes, paper, clothing and other combustibles should be kept more than 3 feet away from the furnace and any other heating equipment. 
• Add 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 trips, have your furnace inspected as soon as possible to diagnose and repair the problem before it results in a furnace fire. 

• Schedule annual furnace maintenance: It isn’t always easy to recognize if your furnace is performing 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 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.