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An Electrician's Warning: Never Plug These Devices into Extension Cords

Extension cords can be great for electronics, but they shouldn't be paired with high-powered device.

Headshot of Corin Cesaric-Epple
Headshot of Corin Cesaric-Epple
Corin Cesaric-Epple Editor
Corin Cesaric-Epple is a Flex Editor at CNET. She received her bachelor's degree in journalism from the University of Missouri-Columbia. Before joining CNET, she covered crime at People Magazine and national and international news at NBC Local Television Stations.
Expertise Home | Health | Energy | Climate Change | AI | Appliances
Corin Cesaric-Epple
4 min read
a surge protector with multiple cords plugged into it

Stop using your extension cords with these common household devices.  

Getty Images/Jeffrey Hazelwood/CNET/

Whether you're looking for the best spot for your air fryer in the kitchen or plugging in a space heater on a cold morning, there's one important thing to remember: Never plug either of those devices into an extension cord or surge protector.

Doing so creates a real fire hazard because those items and other common household devices are high-draw appliances, and forcing that much current through a standard cord is a recipe for disaster. As Paul Martinez, owner of Electrified NYC in Brooklyn, puts it, "No extension cords whatsoever" for any device that heats up or runs constantly.

Not sure which devices pose the biggest risk? Here are seven that you should never plug into an extension cord.

1. Air fryers

Air fryers are great for quickly cooking and warming food, including full meals and side dishes, but it's not a good idea to attach them to an extension cord or power strip. Although they range in watts based on size, large air fryers can draw up to 2,000 watts, making them a major fire hazard if they're plugged into an extension cord.

If you don't have counter space to keep your air fryer out full-time, it's best to only pull it out when needed and plug it into a dedicated wall outlet every time.

2. Microwaves

Many homes have a built-in microwave but not each one has this feature. If you have to find a place to connect yours in your kitchen, this is another heavy-duty appliance that should live on its own dedicated circuit because of its high wattage.

3. Extension cords

A twisted red extension cord

Avoid plugging extension cords into each other.

Raimund Koch/Getty Images

Plugging extension cords into other extension cords is another huge "no" in the electrical world. This practice, called "daisy chaining," can lead to the circuit overheating, which would cause the cords to overheat and lead to a fire.

4. Space heaters

Electric space heaters have long been known to be a major cause of fires. The Consumer Product Safety Commission estimated that between 2017 and 2019, portable space heaters were involved in 1,700 fires per year, with some of those fires resulting in deaths.

"Let's say you connect [an extension cord] to a floor heater, the plug melts and it starts a fire," Martinez said. "That's why you can't use extension cords and/or power strips for any appliances, because they should be used for electronics only."

5. Toasters and toaster ovens

Although toasters are smaller kitchen appliances, they use a lot of energy and can also pose a fire threat if connected to an extension cord or power strip. Toaster ovens need even more power to operate, with wattage ranging from 1,200 to 1,400 watts.

"A lot of people don't have knowledge of extension cords," says Martinez. "If extension cords are 14-gauge and you're running an appliance with a heating element, (like) a toaster oven, microwave or dishwasher, a 14-gauge will not hold the amperage and can burn up the extension cord. And that's what causes fires in New York City."

Dirty toaster

This rule goes for toasters and toaster ovens.

Getty Images

Fourteen-gauge and 12-gauge extension cords are some of the most common extension cords. A 14-gauge cord can handle up to 1,800 watts, or 15 amps, the same as a standard wall outlet in the US. But Martinez recommends that any appliance using more than 1,500 watts should always be on a dedicated circuit.

6. Refrigerators

While refrigerators use less power -- about 300 to 800 watts -- than some other kitchen appliances, they're still not recommended for extension cord use because they are constantly running. Even if an extension cord doesn't cause a fire when attached to a fridge, there's a possibility the connection could cause the fridge to malfunction.

White fridge with healthy foods

While they are not as high-powered as the other kitchen devices, you should still avoid plugging refrigerators into extension cords.

Karen Moskowitz/Getty Images

7. Air conditioning units

AC units use a lot of power to keep your home cool so they need to be plugged into a wall outlet as well. Martinez stresses the importance of purchasing the correct AC unit for your space. You can use an online BTU calculator to determine the type you will need to effectively cool your space.

"People just buy a 5,000 BTU air conditioner, because it's $99 on sale, and they think it's going to cool off (their home), and it does not," Martinez said. "(AC units) are supposed to cycle on and off, so they don't pull that much energy. So if you undersize it, the compressor is going to work 10 times harder." This can result in your home never properly cooling off, a higher electricity bill, and if the unit is connected to an extension cord, possibly a fire.

Air conditioning unit

It is important to determine what size air conditioner unit you need based on the size of the area you are trying to cool off.

James Martin/CNET

The bottom line on extension cords

Martinez said the main thing to keep in mind regarding extension cords is to never use them with any "appliances whatsoever." He also said that your average home extension cords shouldn't be used for anything above 15 amps (1,800 watts), regardless of where or how the device operates. Power strips and surge protectors should only be paired with electronics.

For more home tips, here's how to defend against porch pirates and how to purify your air with houseplants.