Can Furnaces Catch Fire?

The return of low temperatures increases your dependency on home heating equipment in the fall. If your furnace isn’t working properly, it might grow to be a fire hazard and threaten your family’s safety. 

As reported by the National Fire Protection Association (NFPA), heating equipment is a top source of home fires, contributing to approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage every year. Space heaters and fireplaces generate the majority of fires concerning heating equipment, but central heaters, including furnaces, are responsible for just about 12% of these blazes. Find out more about the leading causes of furnace fires and how to avoid them. 

Causes of Furnace Fires

Older furnaces are more exposed to safety hazards since they might be designed differently and slide into disrepair over the years. That being said, 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 various ways. Here are the biggest risks:  

• A clogged filter can block airflow and cause the motor to work more. Eventually, the motor may 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 corroded wiring can cause the voltage to elevate, increasing the chances of an electrical fire. 
• Exceedingly tight or worn motor bearings can heat up whenever the furnace starts. Without adequate lubrication, the bearings could eventually catch fire. 

Blocked Furnace Flue 

Yard waste, animal nests and other materials can obstruct the furnace flue, lowering oxygen. This causes soot building up and bad ventilation, decreasing efficiency and increasing the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts inside your furnace. If this problem continues, your heating equipment could be severely damaged, and the fire may even spread to areas outside the furnace. 

Clogged Heat Exchanger 

The heat exchanger is a closed combustion chamber where the heat produced by your furnace transfers to the air circulating through your home. A heat exchanger clogged up with soot or corrosion has the same effect as a blocked furnace flue—reduced performance and a bigger risk of flame rollout. 

Cracked Heat Exchanger 

Various problems can happen if corrosion cracks the heat exchanger. First, it affects suction within this chamber, leading to less airflow and increased flame rollout. Second, it produces fumes, including carbon monoxide, into your home. Breathing in CO gas can be deadly, so never ignore your carbon monoxide alarms. CO gas can also flash back to the source of the leak and ignite if a flame is found. 

Inadequate Gas Pressure 

Furnaces require a precise combination of natural gas and air to produce 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. 

On the other hand, high gas pressure can produce excessive heat inside 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 combust, here are the steps you can take to avoid furnace fires: 

• Replace the air filter regularly: 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: Periodically check the exterior vent for obstructions and take care of any you find. 
• Don’t keep combustible items close to 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. 
• Add a flame rollout switch: This safety component recognizes if a fire or hot exhaust gases are inside your furnace’s burner compartment. If the rollout switch trips, have your furnace inspected promptly to diagnose and repair the problem before it results in a furnace fire. 

• Request annual furnace maintenance: It isn’t always easy to recognize if your furnace is working 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 pros can inspect, clean and test the system to provide safe operation. If anything seems off, we’ll perform a repair or a modification, offering you peace of mind that your furnace is unlikely to catch fire. For more info or to schedule furnace maintenance, please contact your local Service Experts Heating, Air Conditioning & Plumbing office today.