It was the winter of 2019, and I was in my unfinished basement putting the finishing touches on my band’s next album. I only had to do a few overdubs on the guitar, but my fingers were so cold that I couldn’t play the parts quite right. So I brought a space heater I’d been testing long term for Wirecutter. I placed it on top of the wooden workbench where my digital audio workstation was set up and plugged it into the nearest power strip, which happened to be the same one through which I ran my Marshall half-stack amplifier.
I turned on the heater. Five seconds later, the power bar exploded.
This probably wasn’t the stupidest thing I’ve ever done. But as I watched the sparks fade from the freshly burned mass of plastic in front of me, I knew it was on the menu.
According to the Consumer Product Safety Commission, space heaters cause more than a thousand home fires each year. The National Fire Protection Association puts this number in more context, noting that space heaters account for about 46 percent of home heating-related fires (which include items like water heaters and space heaters) and 88 percent of space heaters-related deaths.
Despite these dire numbers, modern space heaters are actually safer now than they used to be. “The electric heaters I grew up with were an open item,” Linda Hotz, former category manager for the Home Comfort team at home appliance maker De’Longhi, said in a phone call. “Most heaters today are 100 times better, but…they still have a heating element, so they’re not as safe as an air purifier, for example.” Hotz went on to explain that most home space heaters available today (including our picks) need to be approved by an independent safety-testing laboratory like Intertek (whose certification often appears as an “ETL” stamp on the item) or UL. These regulators ensure that heaters have certain safety features built-in, such as a thermal shutoff that automatically cuts off the power when the heater gets too hot.
But as my work has shown, nothing is immune to stupidity. So here are some ways to make sure you’re using your heater safely.
Place the heater on the floor and leave it there
It may be tempting to put the heater on until it blows up in your face. Don’t do this, unless you’re lying on the floor, which is the only place the heater should go. Do not place it on a shelf, chair, or dusty wooden workbench in the basement. And definitely don’t put it on top of your bed, with all those flammable fabrics and feather fillings. If possible, keep it away from the carpet as well.
In general, you should always place your heater on the flat, smoothest surface available. Some of our picks, like the Vornado VH200 and AVH10, are slightly tilted up by default. But you can’t tilt these yourself; As with many space heaters, it comes with flip switches that make it difficult to tilt it. Even if you can find a way around it, don’t do it.
Keep it away from water
This should go without saying, but electricity and water are a deadlier combination than orange juice and toothpaste. So, unless they’re designed and approved — and most aren’t — keep your heater away from all damp areas like kitchens or bathrooms. If you want a warm toilet seat, try a bidet.
Avoid flammable objects as well
The Consumer Product Safety Commission calls it the “3-foot rule,” and it’s pretty simple: Avoid placing your space heater within 3 feet of anything flammable. Some guides list curtains, sheets, furniture, pillows and bedding as things to stay away from. The Association of Home Appliance Manufacturers (AHAM) recommends taking extra precautions, such as keeping flammable materials like paint and matches away. If there is a slight risk of a pillow or other flammable object falling, such as in an earthquake, place the heater where you think the object will not fall.
Never leave your space heater alone in a room
The best way to prevent a fire is to never leave the heater running in a room unattended – that way, if anything goes wrong, you can take action quickly. If you have children or pets that could knock over or clog the heater, monitor its operation closely. The U.S. Fire Administration recommends keeping children at least 3 feet away from a heater. We personally never leave a heater in a room or closet within reach of small children, even if it’s unplugged – beyond a fire hazard, the heater is a 15-amp appliance that draws a lot of amperage. The heater’s plug and cord, along with some intuitive on/off switches, pose an inconspicuous electrical hazard to a curious toddler. Most children learn how to stay away from heat, but few expect to get an electric shock.
Many space heaters also come with instructions warning not to leave them on while you sleep. Many of our picks, like the De’Longhi TRD40615T and Lasko FH500 All Season Comfort Control Tower Fan & Heater in One, come with built-in timers to help you reduce the chance of them running unattended. You can set it to automatically turn off after an hour, for example, so you can sleep in a cocoon of hot air without risking an unattended fire. (Oil-filled radiators like De’Longhi are especially good for bedrooms because they retain heat longer and continue emitting warmth after they are turned off.)
How to Deal with a Cord That’s Too Long (or Not Long Enough)
This is where we start to enter the Goldilocks zone. Most modern space heaters should come with enough slack in the cord that you can plug them into a wall outlet and still place them comfortably in the room for maximum warmth. Note that we specifically said wall outlet: Manufacturers advise against plugging space heaters into surge protectors, extension cords, plug timers, GFCI outlets (the kind with test and reset buttons), or anything that isn’t a wall outlet. These added layers of electrical conductivity can increase the chances of overloading a circuit, or can create additional resistance that allows heat to build up, which can lead to fire or other internal electrical damage. Many manufacturers also recommend keeping your space heater a few feet from the wall where it is attached, to avoid overheating the wall itself. Many of the options in our guide fill the entire room with heat, so you should be able to get adequate performance by using the heater at a safe distance.
Sometimes, you will find yourself experiencing additional slack in the wire. Or perhaps you need to use a wall socket in an adjacent room. In such situations, you should resist the urge to hide the cord from view as it wraps around the corner. Do not place it under a rug or sofa, as this may prevent heat from escaping. You should also try to avoid pinching or bending the wire, such as passing it through a tightly closed door hinge. This can also disrupt the electrical current, contributing to the buildup of heat and energy.
How to add smart controls
As of late 2020, space heaters with built-in smart home functionality are becoming rarer in the United States. But technology and regulatory standards are moving quickly, and we’re told to expect more smart space heater technology in the next year or two.
In the meantime, if you need to turn your heater on or off, either remotely or on a schedule, some of our selections will let you do just that. The Lasko FH500 All Season Comfort Control & Heater in One Tower Fan has built-in digital timers. Our oil-filled radiator pick, the De’Longhi TRD40615T, has a 24-hour analog dial that you can use to set a schedule.
If your space heater lacks a timer — or if you’re determined to only issue heating commands on your voice assistant — consider an additional smart outlet. Most space heater manufacturers discourage people from connecting a space heater to an extension cord or surge protector. But a representative for the Wemo outlet’s manufacturer, Belkin, told us in an interview — confirming our interpretation of the product’s specs — that the plug-in smart outlet should be safe for use with space heaters of up to 15 amps or 1,800 watts of power (most of our picks max out at 1,500 watts). . A Belkin rep added a warning: “Some space heaters with built-in fans may consume more power and cause high amperage flow, which can damage or corrode the switch contacts.” So you should be ready to go, but remember, don’t turn on your heater remotely without first making sure it’s safely positioned, and don’t leave your heater running unattended.
