Can Furnaces Catch Fire

The return of cooler temperatures increases your dependency 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.

As reported by the National Fire Protection Association (NFPA), heating systems are a leading factor of home fires, contributing to nearly 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage every year. Space heaters and fireplaces start most of the fires affecting heating equipment, but central heaters, including furnaces, are responsible for around 12% of these blazes. Learn the leading causes of furnace fires and how to avoid them.

Causes of Furnace Fires

Older furnaces are more vulnerable to safety problems since they might be manufactured differently and slide 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.

Overheated Motor

A furnace motor can overheat in different ways. Here are the biggest risks: 
  • A clogged filter can restrict airflow and force the motor to work longer. Sooner or later, the motor may overheat, elevating the risk of fire.
  • Dirt can collect around and insulate the motor, forcing it to retain heat, which can cause a fire.
  • Exposed or damaged wiring can cause the voltage to elevate, increasing the chances of an electrical fire.
  • Excessively tight or damaged motor bearings can heat up as the furnace runs. Without the appropriate lubrication, the bearings can eventually catch fire.

Clogged Furnace Flue

Yard debris, animal nests and other obstructions can block the furnace flue, lowering oxygen. This results in soot building up and weaker ventilation, decreasing efficiency and increasing the risk of flame rollout. Flame rollout is when fire gets out of the heat exchanger and burns the parts inside your furnace. If this problem continues, your heating equipment can be severely damaged, and the fire could spread to areas outside the furnace.

Clogged Heat Exchanger

The heat exchanger is a restricted combustion chamber where the heat created by your furnace is moved to the air circulating through your home. A heat exchanger clogged 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 occur if corrosion breaks the heat exchanger. First, it affects suction in this chamber, leading to less airflow and increased flame rollout. Second, it emits fumes, including carbon monoxide, into your home. Inhaling CO gas can be lethal, so never neglect your carbon monoxide alarms. CO gas can also return to the source of the leak and ignite if a flame is present.

Inadequate Gas Pressure

Furnaces require a precise 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 causes unwanted condensation within the heat exchanger, increasing the rate of corrosion.
On the other hand, high gas pressure can create excessive heat in the furnace, which can cause the soot inside the heat exchanger to ignite. Such fires can readily spread to other areas.

How to Prevent Furnace Fires

Based on the various ways a furnace can combust, here are the steps you can take to prevent furnace fires:

  • Change 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.
  • Check the furnace flue: Periodically check the exterior vent for obstructions and remove any you find.
  • Don’t place 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 any 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 promptly to diagnose and repair the problem before it results in 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, don't forget furnace maintenance every fall.

Schedule Furnace Services Today

Is it time for your yearly tune-up? Do you need help fixing a problem with your furnace? Whatever the reason, Robinson Service Experts is here for you. Our HVAC pros can inspect, clean and test the system to ensure safe operation. If anything seems off, we’ll suggest a repair or a modification, giving you peace of mind that your furnace is unlikely to catch fire. For more details or to schedule furnace maintenance, please contact your local Robinson Service Experts office today.