Can Furnaces Catch Fire

The return of cooler temperatures boosts your reliance on home heating equipment every fall. If your furnace isn’t functioning correctly, it could become 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, causing nearly 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage each year. Space heaters and fireplaces start the majority of fires concerning heating equipment, but central heaters, including furnaces, are accountable for just about 12% of these blazes. Find out more about the leading causes of furnace fires and how to minimize them.

Causes of Furnace Fires

Old furnaces are more susceptible to safety concerns since they may be manufactured differently and fall into disrepair over the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should know about these causes of furnace fires.

Overheating Motor

A furnace motor can overheat in several ways. Here are the biggest risks: 
  • A clogged filter can block airflow and force the motor to work more. At some point, the motor may overheat, elevating 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 deteriorated wiring can cause the voltage to increase too much, increasing the risk of an electrical fire.
  • Overly tight or damaged motor bearings can heat up when the furnace starts. Without adequate lubrication, the bearings may eventually light on fire.

Clogged Furnace Flue

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

Obstructed Heat Exchanger

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

Cracked Heat Exchanger

Various problems occur if corrosion damages the heat exchanger. First, it reduces suction in this chamber, triggering less airflow and increased flame rollout. Second, it emits fumes, including carbon monoxide, into your home. Inhaling CO gas can be fatal, so never dismiss your carbon monoxide alarms. CO gas can also flash back to the source of the leak and ignite if a flame is present.

Improper Gas Pressure

Furnaces require an accurate combination 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 causes unwanted condensation inside the heat exchanger, increasing 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 easily 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 prevent furnace fires:

  • Replace the air filter regularly: Check the filter once a 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 clear out any you find.
  • Don’t place combustible items close to the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept more than 3 feet away from the furnace and all other heating equipment.
  • Install a flame rollout switch: This safety device recognizes if a fire or hot exhaust gases are inside your furnace’s burner compartment. If the rollout switch triggers, have your furnace inspected right away to diagnose and repair the problem before it causes a furnace fire.
  • Schedule annual furnace maintenance: It isn’t always easy to notice if your furnace is operating unsafely. Whether you notice warning signs or not, prioritize 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 reason, Service Experts Heating & Air Conditioning is here for you. Our HVAC professionals can inspect, clean and test the system to provide safe operation. If anything looks out of place, we’ll recommend 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 office today.