Can a Window Air Conditioner Catch Fire?

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In a 2021 report, the National Fire Protection Association reported that, between 2015 and 2019, there were 2,800 air conditioner fires each year. These resulted in 40 deaths and 120 injuries annually, not to mention $86 million in direct property damage.1 The answer to the question “Can a window air conditioner catch fire?” is an absolute yes. 

A window AC unit has a higher risk of catching fire than a central AC system. Knowing the causes of such fires can help us understand how to prevent them. Here are some reasons an air conditioner may catch fire:

Electrical Problems

Many fires related to window air conditioners are associated with electrical wires or their insulation. If a wire or cable is old, damaged, or loosely connected, sparks can occur and overheating can ignite a fire. Sparks can also start fires when they strike flammable material such as window treatments, fabric, carpeting, etc. 

Fires may also start when extension cords are misused. These are not for powering window ACs. Extension cords are recommended for only temporary use. If you need an extra socket or power for your air conditioner, it’s best to have a licensed electrician install a dedicated circuit. Power strips and plug splitters pose AC safety hazards as well.


A window AC can catch fire if it overheats due to mechanical issues. Dirt and debris inside the unit can create friction and coat elements that overheat as a result. Blocked airflow from a clogged filter can cause the fan to work harder to pull air in. Motor bearings that aren’t properly lubricated can overheat as well. The increased risk of an air conditioner fire is another reason to stay current with AC maintenance.

Improper Installation

A poorly installed window air conditioner can potentially fall out of its mounting. Not only can the impact cause a serious injury or major property damage. It can lead to a home fire. Refrigerant leaks and electrical hazards are other concerns. Always hire a professional to install an air conditioner. They’ll make sure the unit is installed and connected properly, and ensure it leans slightly outside so water does not drip on electrical components.

Preventing a Window Air Conditioner from Catching Fire

Professional installation is one way to prevent a fire; other preventative measures include:

  • Never run an air conditioner cord under a rug, door, or through a wall.
  • Do not power it with an extension cord.
  • Schedule annual service by a reputable AC contractor.
  • Turn the AC off during peak electrical usage.
  • Change the filter once a month.
  • Check the exterior for leaves, debris, and bugs and clean if necessary.

If your home still uses fuses, don’t install a larger fuse to stop it from blowing. Update to a circuit breaker panel that can safely deliver power to your air conditioner. Follow all recommended fire safety measures as well, such as keeping a fire extinguisher handy, installing smoke detectors, and replacing their batteries every year.

Schedule AC Service in Phoenix

Hays Cooling, Heating & Plumbing provides dependable air conditioning repair, maintenance, and installation. We can address wear before the summer heat arrives, allowing our customers to benefit from routine care that ensures their safety and comfort. Some clients ask “Can a window air conditioner catch fire?” We know it can if it’s not installed and cared for properly. Schedule air conditioning services in the Phoenix Valley online or call 602-610-0590 today.