The return of cooler temperatures raises your dependence on home heating equipment every fall. If your furnace isn’t functioning correctly, it may develop into a fire hazard and endanger your family’s safety.
According to the National Fire Protection Association (NFPA), heating systems like furnaces are a leading cause of home fires, contributing to nearly 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage each year. Space heaters and fireplaces generate the majority of fires affecting heating equipment, but central heaters, like furnaces, are liable 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
Old furnaces are more vulnerable to safety hazards because they might be configured differently and settle into disrepair through the years. That being said, whether your furnace is more than a decade old or brand new, you should be aware of these causes of furnace fires.
Overheating Motor
A furnace motor can overheat in several ways. Here are the main risks:
- A clogged filter can restrict airflow and cause the motor to work longer. At some point, the motor can overheat, raising the risk of fire.
- Dirt can collect around and insulate the motor, forcing it to retain heat, which can lead to a fire.
- Exposed or corroded wiring can cause the voltage to elevate, increasing the chances of an electrical fire.
- Excessively tight or worn motor bearings can heat up whenever the furnace is on. Without adequate 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 leads to soot accumulation and bad ventilation, lowering efficiency and increasing the risk of flame rollout. Flame rollout is when fire gets out of the heat exchanger and burns the parts in your furnace. If this problem remains, your heating equipment can 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 through your home. A heat exchanger clogged with soot or corrosion has the same result 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 lowers suction within this chamber, triggering less airflow and increased flame rollout. Second, it releases 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 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 leads to unwanted condensation inside the heat exchanger, increasing the rate of corrosion.
Conversely, high gas pressure can produce 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 different 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 appears dirty or every three months, whichever comes first.
- Check the furnace flue: Periodically check the exterior vent for obstructions and clear out any you find.
- Don’t place 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 any other heating equipment.
- Install 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 triggers, have your furnace inspected as soon as possible to diagnose and repair the problem before it results in a furnace fire.
- Request 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 yearly tune-up? Do you need help resolving a problem with your furnace? Whatever is happening, Stevenson Service Experts 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 recommend a repair or a modification, providing you peace of mind that your furnace is unlikely to catch fire. For more information or to schedule furnace maintenance,
please contact your local Stevenson Service Experts office today.