Can Furnaces Catch Fire

The return of low temperatures boosts your reliance on home heating equipment in the fall. If your furnace isn’t functioning correctly, it may develop into a fire hazard and threaten your family’s safety.

As stated by the National Fire Protection Association (NFPA), heating systems like furnaces are a leading source of home fires, leading to nearly 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage annually. Space heaters and fireplaces cause most of the fires affecting heating equipment, but central heaters, including furnaces, are liable for around 12% of these blazes. Find out more about the most likely causes of furnace fires and how to minimize them.

Causes of Furnace Fires

Aging furnaces are more exposed to safety concerns since they might be manufactured 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 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 impede airflow and force the motor to work more. Eventually, the motor may overheat, increasing the risk of fire.
  • Dirt can accumulate around and coat the motor, forcing it to hold heat, which can lead to a fire.
  • Exposed or corroded wiring can cause the voltage to get too high, increasing the chances of an electrical fire.
  • Exceedingly tight or worn motor bearings can heat up when the furnace runs. Without the proper lubrication, the bearings may eventually light on fire.

Clogged Furnace Flue

Yard waste, animal nests and other materials can obstruct the furnace flue, lowering oxygen. This results in soot building up and improper 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 remains, your heating equipment may be badly 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 produced by your furnace is moved to the air circulating throughout your home. A heat exchanger blocked with soot or corrosion has the same result as a blocked furnace flue—reduced performance and a bigger risk of flame rollout.

Cracked Heat Exchanger

Numerous problems can happen if corrosion cracks the heat exchanger. First, it reduces suction inside this chamber, leading to less airflow and increased flame rollout. Second, it emits fumes, like carbon monoxide, into your home. Inhaling CO gas can be deadly, so never neglect 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 need a precise mixture 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 leads to unwanted condensation within the heat exchanger, accelerating the rate of corrosion.
Conversely, high gas pressure can create excessive heat in the furnace, which can cause the soot inside the heat exchanger to burn. Such fires can quickly spread to other areas.

How to Prevent Furnace Fires

Based on the listed ways a furnace can light on fire, here are the steps you can take to avoid 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: Inspect the exterior vent for obstructions and take care of any you find.
  • Don’t keep combustible items close to the furnace: Things including cardboard boxes, paper, clothing and other combustibles should be kept more than 3 feet away from the furnace and all other heating equipment.
  • Put in 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 as soon as possible to diagnose and repair the problem before it causes a furnace fire.
  • Schedule annual furnace maintenance: It isn’t always easy to recognize 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 the reason, Service Experts Heating & Air Conditioning is here for you. Our HVAC experts can inspect, clean and test the system to provide safe operation. If anything doesn't seem right, we’ll recommend a repair or a modification, giving 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 office today.

 

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