Every year, fire departments throughout the U.S respond to nearly 47,000 home electrical fires, hundreds of them fatal, according to the National Fire Protection Association (NFPA). Overloaded electrical outlets are a common cause of the blazes, especially these days with so many high-powered electronic devices running in our homes, from air fryers to hair multi-stylers.
A voltage overload will usually cause the circuit breaker to trip, cutting power to the outlet. That’s if you’re lucky. In a worse-case scenario, an overload can also cause “overheating, burning, or melting of an electrical outlet,” warns Braden Welch, an electrical expert with American Home Shield, the home warranty company. In extreme cases, he adds, wire insulation will become damaged, “which can expose conductors and increase the risk of electrical arcing and fire.”
It can even be dangerous to use multiple high-wattage devices in the same part of the house. “The important thing to remember is that outlets in the same area, or even in different rooms, may be connected to the same circuit,” explains says Susan McKelvey, NFPA’s Communications Manager. “If you’re unsure what outlets are on a particular circuit, consult a qualified electrician.”
To help you avoid the hazards of electrical overloads, our experts in the Good Housekeeping Home Improvement & Outdoor Lab, along with outside safety experts, pulled together a list of devices that should never be plugged into outlets on the same circuit—or even into a power strip that’s plugged into the wall.
Countertop appliances that heat up
A good rule of thumb: if it hums, it heats. Think air fryers, toaster ovens, griddles, and pressure cookers. Each of these appliances can easily use 1,000 watts of power in active heating mode. Given that the safe limit for continuous use with a standard 15-amp, 120-volt electric outlet is around 1,500 watts, you see how plugging two heat-generating appliances into the same outlet can lead to serious problems.
To avoid reaching that danger point, “homeowners should be aware of potential warning signs, such as frequently tripped breakers, outlets or plugs that feel unusually warm, discoloration around an outlet, or a burning odor,” says McKelvey.
Hairstyling tools
First, you dry your hair, then you curl it. Or maybe you’re drying while your roomie volumizes. In each of these hairstyling scenarios, it’s best to plug the tools into separate outlets. Our experts in the Good Housekeeping Institute Beauty Lab routinely test hairdryers that get as high as 2,000 watts. Most bathrooms have 20-amp outlets, which can handle up to 2,400 watts. So, the hairdryer on its own should be fine. But if you add in a high-powered multi-styler, that can easily push the socket beyond its breaking point.
Anything that runs on a compressor
Refrigerators and air conditioners are the main culprits here, since they both use a compressor to circulate refrigerant through their systems. When the compressor kicks on at the start of every cycle, it causes a massive surge in power. So, if you have two of these appliances plugged into the same outlet (a portable AC and a mini fridge is a likely duo), the power draw will overwhelm the outlet, causing it to flip a switch or, worse, malfunction, melt down, and eventually ignite.
Portable heaters of any size
If you’re trying to warm a large space, you might try running two space heaters at the same time. That’s fine, so long as they’re not plugged into the same outlet or power strip. Even the smallest space heaters from our tests require 750 watts, so a pair of them will overheat a standard 15-amp outlet. And most of the models we test are 1,500 watts or more. Two of those heat blasters will be too much for even a larger 20-amp outlet.
Corded power tools
Let’s say you’re in the workshop, doing some woodwork with a friend. You’re on the circular saw; they’re handling the router. The combined wattage on those corded power tools could be up above 3,000, so you won’t be powered up for long if they’re plugged into the same outlet. That is, unless the workshop is outfitted with dedicated 20-amp, 240-volt circuits, which can handle loads of 4,800 watts.
Having written thousands of product reviews and how-to articles on all aspects of home ownership, from routine maintenance to major renovations, Dan (he/him) brings more than 20 years of industry experience to his role as the director of the Home Improvement & Outdoor Lab at the Good Housekeeping Institute. A one-time roofer and a serial remodeler, Dan can often be found keeping house at his restored Brooklyn brownstone, where he lives with his wife and kids.
