Can Furnaces Catch Fire?

The return of cold temperatures increases your dependence on home heating equipment each fall. If your furnace isn’t functioning properly, it might become a fire hazard and jeopardize your family’s safety.

According to the National Fire Protection Association (NFPA), heating systems like furnaces are a major factor of home fires, contributing to approximately 50,000 blazes, 500 civilian deaths and more than $1 billion in direct property damage annually. Space heaters and fireplaces start most of the fires concerning 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 minimize them.

Causes of Furnace Fires

Older furnaces are more exposed to safety problems as they could be configured differently and fall into disrepair through the years. Nevertheless, whether your furnace is more than a decade old or brand new, you should know about these causes of furnace fires.

An Overheated Motor

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

    • A clogged filter can restrict airflow and force the motor to work longer. Sooner or later, the motor might overheat, raising the risk of fire.
    • Dirt can gather around and cover up the motor, forcing it to hold heat, which can lead to a fire.
    • Exposed or deteriorated wiring can cause the voltage to get too high, increasing the chances of an electrical fire.
    • Overly tight or damaged motor bearings can heat up whenever the furnace runs. Without the appropriate lubrication, the bearings may eventually light on fire.

Clogged Furnace Flue

Yard waste, animal nests and other obstructions can block the furnace flue, lowering oxygen. This leads to soot accumulation and weaker ventilation, decreasing efficiency and increasing the risk of flame rollout. Flame rollout is when fire escapes the heat exchanger and burns the parts within your furnace. If this problem remains, your heating equipment can be severely damaged, and the fire may even spread to areas outside the furnace.

Clogged 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 up 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

Several problems can happen if corrosion breaks the heat exchanger. First, it lowers suction inside this chamber, triggering less airflow and increased flame rollout. Second, it produces fumes, including carbon monoxide, into your home. Inhaling CO gas can be lethal, so never dismiss your carbon monoxide alarms. CO gas can also return to the source of the leak and ignite if a flame is found.

Improper Gas Pressure

Furnaces require a precise mixture 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 within the heat exchanger, increasing the rate of corrosion.

On the other hand, high gas pressure can lead to 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 light on fire, here are the steps you can take to prevent furnace fires:

    • Change the air filter consistently: Check the filter each month and change it when it appears dirty or every three months, whichever comes first.
    • Keep an eye on the furnace flue: Periodically check the exterior vent for obstructions and clear out any you find.
    • Don’t keep combustible items close to the furnace: Things such as cardboard boxes, paper, clothing and other combustibles should be kept at a minimum 3 feet away from the furnace and all other heating equipment.
    • Add 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 trips, have your furnace inspected right away 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 operating 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 fixing 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 seems off, we’ll suggest 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 & Plumbing office today.

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