Short answer
A plug-in wall heater is a small electric heater that plugs into a standard outlet and warms one room with a ceramic element, a fan and a thermostat, with nothing to install. Before you buy, check overheat protection, tip-over shut-off, adjustable heat, a timer, the voltage and the guarantee. Then give it a wall outlet of its own.
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The living room is warm, but the spare room, the home office or the corner of the bedroom never quite catches up. Heating the whole house for one cold room feels like too much, and if you rent, cutting into a wall to fix it is not an option. That is the job a plug-in wall heater is made for: it goes into an outlet, and the room starts to warm.
This guide explains what these heaters are, how they work in plain words, who they suit and what to check before you buy one. Near the end I show where two heaters I have reviewed fit, the Ultra Air Heater and the CosyJet. I am not an electrician, so the outlet and wiring points follow the Department of Energy and the manuals.
What is a plug-in wall heater?
It is a compact electric heater that plugs straight into a standard wall outlet, with no wiring and no tools. The U.S. Department of Energy describes space heaters as units that give supplemental heat to a specific room, used when the main heating system is not enough or when central heating is too costly to install or run. A plug-in wall heater is the smallest version of that idea: light enough to carry, simple enough to set up in a minute.
How does a plug-in wall heater work?
Three parts do the job, and most models share them:
- A ceramic element makes the heat. Many plug-in heaters use a PTC ceramic element (PTC stands for Positive Temperature Coefficient). The producer of the Ultra Air Heater says its PTC element shuts down automatically when it detects overheating. My guide to ceramic vs infrared heaters shows how ceramic heat compares with other types.
- A small fan moves the warm air. The Ultra Air Heater’s official page describes an internal fan that sends the heat out into the room.
- A thermostat and heat settings keep it where you like it. You choose the temperature on the display, and some models add a timer. The CosyJet, for example, has a built-in thermostat, a digital display and a timer from 1 to 9 hours.
The routine is the same every time: plug in, set the heat, feel the warmth. There is nothing to assemble and nothing to install.
Who is a plug-in wall heater for?
- One room is the cold one. The spare room, the home office or the corner of the bedroom that never keeps up with the rest of the house. If it stays cold even with the heating on, read why one room is always colder first; the cause is sometimes a draft you can fix for a few dollars.
- You rent. Nothing to drill, nothing to wire, nothing to leave behind when you move.
- You like to move things around. Unplug it, take it to the next room and plug it in again.
- You want to set it once. A thermostat and a timer do the remembering for you.
It is a room heater: each unit warms the room it is in, which is why multi-unit packs put one in each room you use most.
What should you check before you buy a plug-in wall heater?
Seven things matter more than the brand name. Here they are, with what the Ultra Air Heater and the CosyJet say on their official pages:
| Check this | Why it matters | Ultra Air Heater | CosyJet |
|---|---|---|---|
| It plugs straight into the wall | No installation, and the heater gets the outlet to itself | A wall outlet is all it needs | Plugs into a wall outlet, nothing to assemble |
| Overheat protection and tip-over shut-off | The heater stops itself if it gets too hot or is knocked over | PTC element that shuts down on overheating; stops heating and cuts the power if it falls over | A built-in safety system, as the producer describes it |
| Adjustable heat | You choose the comfort level instead of one fixed setting | Adjustable heat settings with a thermostat | Built-in thermostat and digital display |
| A timer | It switches itself off when you are done | Timer buttons on the display | Timer from 1 to 9 hours |
| Size and weight | You will carry it from room to room | Compact and light | 129.5 x 91 x 144.5 mm, 442 g |
| Your country and your outlet | The official site ships only to certain countries, and the heater has to match your outlet | Ships to the US, Canada, Puerto Rico, the Bahamas and Panama; confirm the voltage on the official page against your outlet | Ships to the UK, Germany and Austria; confirm the voltage on the official page against your outlet |
| Guarantee and support | Time to try it in your own room | 60-day money-back guarantee | 30-day money-back guarantee |
One more habit that pays off: buy from the official website. That is where the guarantee, the support and the current price live, and it is where the buttons in this guide take you.
How do you use a plug-in wall heater?
Plug it in, pick the heat you like and set the timer if your model has one. The official pages add a few rules worth following:
- Plug it directly into a wall outlet. The Ultra Air Heater’s official page says to use a wall outlet rather than an extension cord or a power strip, and to keep other devices off the same outlet.
- Do not leave it on unattended. The producer says this about any heater, and notes that the surface can be hot to the touch.
- Follow the instructions that come with your model.
For where to stand it and how much open floor it needs, see where to put a space heater. With a heater at home and children or pets around, space heaters with pets and kids has the setup rules.
How many plug-in heaters do you need?
One for each room you want to warm. Moving a single heater back and forth works too, since it is light, but one unit in the office and one in the bedroom saves the carrying. Multi-unit packs bring the price per unit down: the Ultra Air Heater drops to $35.28 a unit in the three-unit option, for example.
To see what any heater costs to run, multiply its kilowatts by the hours you use it and by your price per kilowatt-hour. The electricity guide has the table, and the central heating comparison explains how zone heating works.
Where do the Ultra Air Heater and the CosyJet fit?
I have reviewed two plug-in heaters on this site, and they suit different jobs and are sold in different countries, so the one you can order depends on where you live. Everything below comes from what each producer says about its own heater.
Ultra Air Heater: one cold room, nothing to install
Sold in the United States, Canada, Puerto Rico, the Bahamas and Panama. The Ultra Air Heater is a compact plug-in heater with a PTC ceramic element, an internal fan, adjustable heat settings and a thermostat. The official page lists overheat protection, and if the heater tips over it stops heating and cuts the power. It is made for one room at a time: plug it in near where you sit, set the heat and let it work. Every order carries a 60-day money-back guarantee.
On the official website one unit costs $44.10, two cost $88.20 and three cost $105.84 in US dollars, which is $35.28 a unit. Those prices include the extra 10% savings the official page applies, and prices are set by the producer and can change. My Ultra Air Heater review has the details and my 4.3/5 score.
CosyJet: a small heater for your desk or bedside
Sold in the United Kingdom, Germany and Austria. The CosyJet is a plug-in heater the size of a coffee-mug box (129.5 x 91 x 144.5 mm, 442 g) with a built-in thermostat, a digital display and a timer from 1 to 9 hours. The producer describes a durable, heat-resistant housing and a built-in safety system. It warms the spot around you rather than a whole room, which suits a desk, a bedside or a cold corner. The official website states a 30-day money-back guarantee. In the UK one CosyJet costs £69.95 and the price drops to £59.50 a unit in the four-pack; in Germany and Austria it is €69.95 and €59.50. Prices are set by the producer and can change. My CosyJet review has the details and my 4.1/5 score.
Which plug-in heater should you choose?
Start with where you live, because each heater ships only to its own countries:
- United States, Canada, Puerto Rico, the Bahamas or Panama: the Ultra Air Heater, to warm one cold room, with adjustable heat, overheat protection, a price per unit that drops in the three-unit option and 60 days to try it.
- United Kingdom, Germany or Austria: the CosyJet, to warm the spot where you sit, at a desk or a bedside, with a timer up to 9 hours and 30 days to try it.
Anywhere else, the seven checks above work for any plug-in heater you find locally.
Still comparing types? The pillar guide covers how to choose by room size, and the winter checklist goes through the whole house, room by room. For everything else I have researched, browse all Vitherma guides and read how I research and write.
Product photos by the producers.
Frequently asked questions
What is a plug-in wall heater?
A compact electric heater that plugs straight into a standard wall outlet, with no wiring, no tools and no installation. It gives supplemental heat to one room, which is how the U.S. Department of Energy describes space heaters.
How does a plug-in wall heater work?
Most models combine a ceramic heating element, a small fan that moves the warm air and a thermostat with heat settings. You plug it in, choose the temperature on the display and, if your model has one, set a timer.
Do plug-in wall heaters need to be installed?
No. A wall outlet is all they need, which is why they suit renters and anyone who prefers not to drill or wire anything.
Can a plug-in wall heater warm a whole room?
It is made for one room at a time. The Ultra Air Heater is built to warm the room it is in, and the CosyJet warms the spot around you, such as a desk or a bedside. For a second room, use a second unit.
Can I use an extension cord or a power strip with a plug-in heater?
The Ultra Air Heater’s official page says to plug the heater directly into a wall outlet, not into an extension cord or a power strip, and not to plug other devices into the same outlet. Follow the instructions that come with your model.
What should I check before buying a plug-in wall heater?
Seven things: that it plugs straight into the wall, overheat protection and tip-over shut-off, adjustable heat, a timer, its size and weight, the voltage against your outlet and the guarantee. Buy from the official website, where the guarantee and support are.
Where can I buy the Ultra Air Heater and the CosyJet?
On their official websites, which ship to different countries. The Ultra Air Heater is sold in the United States, Canada, Puerto Rico, the Bahamas and Panama. The CosyJet is sold in the United Kingdom, Germany and Austria.
How much does the Ultra Air Heater cost?
On the official website one unit costs $44.10, two cost $88.20 and three cost $105.84 in US dollars, which is $35.28 a unit. These prices include the extra 10% savings the official page applies, and every order carries a 60-day money-back guarantee. Prices are set by the producer and can change.
How much does the CosyJet cost?
In the UK one CosyJet costs £69.95 and the price drops to £59.50 a unit in the four-pack. In Germany and Austria the prices are €69.95 and €59.50. Every order carries a 30-day money-back guarantee. Prices are set by the producer and can change.
Ultra Air Heater or CosyJet: which one should I choose?
It depends on where you live. The Ultra Air Heater is the one sold in the United States, Canada, Puerto Rico, the Bahamas and Panama, and it warms one room with adjustable heat. The CosyJet is the one sold in the United Kingdom, Germany and Austria, and it warms your desk or bedside with a timer from 1 to 9 hours.
Is this electrical advice?
This guide summarizes what the U.S. Department of Energy publishes, plus the producers’ own statements about the Ultra Air Heater and the CosyJet. I am not an electrician, so follow the instructions that come with your model.