Updated 24 May 2011

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Introduction

Price isn't the only factor when you're buying an electric heater.

Electric heaters convert all the electricity they consume into heat. So why do we bother testing them instead of recommending you just buy the cheapest? The answer is that electric heaters vary in how well they heat a room.

We've tested 10 models: 8 oil-column heaters, 1 electric element in a vented-box arrangement, and 1 oil-column look-a-like where the fins contain air instead of oil.

Models we tested

This report contains test results and recommendations for the following electric heaters:

Checklist

If you're thinking of buying an oil-filled or conventional convection heater, here's what to consider.

Will it suit your needs?

All electric heaters are 100 percent efficient. That is, every kilowatt of electrical energy they use is given off as heat. But how warm they make you feel depends on the type of heater – and house.

Convection heaters are designed to heat the air in a room and distribute it as evenly as possible. They're good for background warmth, especially in well-insulated modern houses. For an older, draughty, high-ceilinged home you're better off using radiant heaters – which shine the heat at you.

For more information on what type of heater you need, see our guide to choosing a heater. To work out what size heater you need, see our calculator.

How they work

Convection heaters warm the air around the heater. This warm air then rises and is replaced by cooler air which is in turn heated. While this means all convection heaters create a certain amount of air movement, it's not usually enough to distribute the warmth evenly throughout the room.

The result is a room where the warmest air tends to be near the ceiling and the coldest at the floor. Fans stir up the air and help even out this temperature layering – but at the cost of extra noise.

Features to look for

Controls
The controls should be clearly visible, easy to access and easy to use. Markings should be easy to read with good contrast. The more heat settings the better – you'll have more flexibility to control the room temperature.

Timer
With a timer, you can warm up a living area before your get up in the morning or arrive home from work. You can also have a bedroom heater turn itself off after you've gone to sleep.

Fan
A fan is an effective way to break up the layers of cold and warm air in a room. While noisy, you don't have to use them continuously. Just switch them on for a few minutes, to warm up the room.

Frost watch
This apparently maintains a temperature of 5°C if the thermostat is left on its lowest setting, avoiding frost. We can't quite see the purpose, unless you want to keep your heater in the glasshouse, or maybe in a conservatory, to protect special plants from frost damage.

Mobility
Oil-filled heaters are heavy and can be difficult to move around because of their size and shape. Try moving the heater around in the shop. There is usually a recessed handle at the control panel end: it should give a good grip.

Some models have 4 castors, others a combination of castors and wheels. Some have a single pair of large wheels at one end, so you have to lift the handle end to move the heater. Weight then becomes important.

Clothes drying
Clothes must not be draped over a heater. Some heaters come with a detachable drying rack that spaces the clothes away from the heater. For others, you can buy a separate drying rack.

Thermostat
This maintains a desired average room temperature (as long as it's within the heater's capacity), and should have a control that's easy to read and set.

Cord storage
This allows you to stow the cord neatly when the heater is not in use.

Safety

Oil-filled heaters
The relatively low surface temperature makes oil-filled heaters safer than most other types of heater. But some models, following early designs, have narrow exposed fins that get quite hot. Safer, these days, are the models with wide flat fins, or a casing over the fins, and a protective heat shield at each end.

Because they are tall and narrow, column heaters are inherently less stable than other types. They are also heavy. If a model with narrow exposed fins topples onto a small child, it can do quite a lot of harm. Having wide or enclosed fins helps. A tapered shape may help stability.

If there are toddlers about, a loop of chain around the top fin tube and attached to a wall could stop a nasty accident if the child tried to pull the heater over.

Tilt switch
Portable electric convection heaters are a safe choice for background heating – but they must have a tilt switch. If a heater fitted with a tilt switch falls over, it simply switches off.

Tilt switches should be mandatory for all portable electric heaters. Unfortunately they aren't.

Thermal cutout
Some models have a built-in thermal cutout, to turn the heater off if it overheats.