Can Furnaces Catch Fire?

The return of cooler temperatures increases your dependence on home heating equipment every fall. If your furnace isn’t operating correctly, it could grow to be a fire hazard and threaten your family’s safety. 

According to the National Fire Protection Association (NFPA), heating equipment is a top source of home fires, leading to almost 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage each year. Space heaters and fireplaces cause most of the fires involving heating equipment, but central heaters, including furnaces, are accountable for around 12% of these blazes. Learn more about the primary causes of furnace fires and how to prevent them. 

Causes of Furnace Fires

Older furnaces are more vulnerable to safety hazards since they may be configured 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 know about these causes of furnace fires. 

Overheated Motor

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

• A clogged filter can impede airflow and force the motor to work more. Eventually, the motor can overheat, elevating the risk of fire. 
• Dirt can accumulate around and insulate the motor, forcing it to retain heat, which can trigger a fire. 
• Exposed or deteriorated wiring can cause the voltage to increase too much, increasing the likelihood of an electrical fire. 
• Exceedingly tight or damaged motor bearings can heat up as the furnace starts. Without the appropriate lubrication, the bearings could eventually catch fire. 

Blocked Furnace Flue 

Yard debris, animal nests and other obstructions can clog the furnace flue, restricting oxygen. This causes soot buildup and weaker ventilation, limiting 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 persists, your heating equipment may be seriously damaged, and the fire could spread to areas outside the furnace. 

Clogged Heat Exchanger 

The heat exchanger is a sealed combustion chamber where the heat produced by your furnace is moved to the air circulating throughout your home. A heat exchanger clogged with soot or corrosion has the same result as a blocked furnace flue—reduced performance and an increased risk of flame rollout. 

Cracked Heat Exchanger 

Numerous problems occur if corrosion damages the heat exchanger. First, it affects suction inside this chamber, leading to less airflow and increased flame rollout. Second, it emits fumes, such as carbon monoxide, into your home. Breathing in CO gas can be lethal, 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 lit. 

Improper Gas Pressure 

Furnaces require an exact mixture of natural gas and air to produce 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 within the heat exchanger, increasing the rate of corrosion. 

On the other hand, high gas pressure can create 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 listed ways a furnace can catch fire, here are the steps you can take to prevent furnace fires: 

• Change the air filter on a regular basis: Check the filter each month and change it when it seems dirty or every three months, whichever comes first. 
• Check the furnace flue: Inspect the exterior vent for obstructions and take care of any you find. 
• Don’t place combustible items near 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 promptly to diagnose and repair the problem before it results in a furnace fire. 

• Schedule annual furnace maintenance: It isn’t always easy to tell 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 annual 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 professionals can inspect, clean and test the system to guarantee 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.