Most electric heaters are relatively cheap to buy, but more expensive to run than heat pumps or wood burners.
- When to use electric heaters
- Types of electric heaters
- Checklist for electric heaters
- How much does an electric heater cost to run?
- Using electric heaters wisely
Electric heaters can be suitable:
- for smaller rooms and rooms you only heat occasionally, like bedrooms.
- to replace portable LPG heaters or open fires - electric heaters are much safer and cheaper to run.
The heating capacity of electric plug-in heaters is typically no more than 2.4 kW (=2400 Watts). This means that you may need to run more than one heater in larger or poorly insulated rooms. Only use one heater per power outlet to avoid overloading.
With the exception of heat pumps, all electric heaters are equally efficient. They convert all the electricity they consume into useful heat - so don't believe claims that any one type of electric heater is more efficient than the other. Having said that, choosing the right type of heater for the situation is important to get the full benefit of all of the heat you're paying for.
Flat-panel heaters are often promoted as ‘eco’ or cheap to run. However they produce very little heat - usually not enough to heat up a room to comfortable and healthy temperatures. A higher wattage heater controlled by a thermostat is usually a better alternative to panel heaters - you can turn off a higher wattage heater when you don’t need it and the heater will be able to heat up the room again within a reasonable time. A thermostat can cycle the heater on and off so you can maintain a comfortable temperature without wasting energy.
- Low surface temperature - panel heaters usually don't get hot enough for children or pets to burn themselves, but covering them with towels or clothes still poses a fire risk.
- Can take a very long time to heat up a cold room - because of their very low heat output.
- Good for heating very small rooms continuously - like bathrooms or small studies. However, leaving the heater on when you’re not there will result in unnecessarily high power bills.
- Often don’t have a thermostat.
Convection and oil column heaters
Convection and oil column heaters mostly heat air rather than surfaces. The hot air rises and then slowly circulates around the room, providing background warmth. Oil-column heaters also provide some radiant heat.
- Usually have a thermostat - good for quiet background heating.
- Good for heating bedrooms overnight - quietly on a thermostat.
- Struggle to heat rooms with high ceilings evenly and effectively.
- Can take a long time to heat up a cold room - because the heated air rises and collects beneath the ceiling, reaching the lower parts of the room only slowly. A fan or fan heater can be used to mix the heated air more effectively during the warm up period.
- May have a built-in fan to mix the air more effectively. Built-in fans are often small and not as effective as some fan heaters.
- Surface temperatures of convection and oil-column heaters are lower than micathermic and radiant heaters - so they’re safer, but still get hot enough to burn skin.
- Safety first - convection heaters can easily be tipped over and the weight and sharp fins of oil column heaters can be dangerous to children. Some heaters can be fixed to a wall.
- Provide heat in a similar way as oil-column heaters.
- Heat up quicker than oil-column heaters.
- Their exterior can get quite hot. This can be a hazard for children.
- Lightweight and easy to move around.
Bar heaters with glowing elements and a reflector are radiant heaters. They mainly heat objects and people rather than air in a room, and are available as either free-standing, wall or high-wall mounted models.
- Good for rooms with high ceilings.
- Good for large rooms where you only need to heat one area of the room.
- Great for instant heat - rather than waiting for the air to warm up. For example in large bathrooms (only use high wall mounted models here), while standing at the kitchen sink or for that quick early morning breakfast in a cold house.
- Not suitable for bedrooms - many emit some visible light and they can also be a fire risk.
- Can be a fire risk and dangerous to children.
- High-wall mounted models (available from electrical supply stores) can be installed out of children’s reach and away from flammable materials. They are also more effective than high-wall fan heaters in bathrooms, provided there is enough space for the required safety clearances.
- Most don’t have a thermostat.
Fan heaters (or ceramic heaters) can be noisy, but distribute heated air around your room rather than letting it form a layer of hot air below the ceiling.
- Fan heaters can boost convection heaters - providing additional heat and distributing the heated air more evenly, so your room feels warm quicker.
- The bigger the fan, the better the heated air will mix around the room.
- They provide quick warmth in smaller rooms - for example the kitchen or bathroom in the morning, where you need heating for very short periods of time.
- High-wall mounted models are good for bathrooms, especially ones that are too small for installing a high-wall mounted radiant heater.
- Most don't have a thermostat.
Electric underfloor heating
- Cheaper to install than hydronic underfloor heating (where heated water flows through pipes embedded in the floor).
- Expensive to run.
- Easily retrofitted into existing homes - between your floorboards and the floor covering. Can also be installed in new homes.
- Floor must be well insulated, otherwise much of the heat you pay for will be lost.
- Can take a long time to heat up a room.
- Commonly installed in bathrooms - however, if you only want to heat intermittently, a high-wall radiant or fan electric heater will heat the bathroom up much quicker than underfloor heating.
- Underfloor heating provides very comfortable heat.
The higher a heater’s wattage, the more heat it will produce. Choose a heater with enough wattage to heat up your room within a reasonable timeframe. The table below gives a rough guide. If in doubt, get a heater with a higher wattage and a thermostat. The maximum available wattage of plug-in electric heaters is 2400 Watts.
|Room size||Heater Wattage required|
|Tiny (up to 4m2)||500 W|
|Very small (up to 7 - 8m2)||1000 W|
|Small (up to 10 - 13m2)||
|Small/Medium (up to 13 - 17m2)||
|Medium (up to 16 - 20m2)||
- Help maintain an even temperature and conserve electricity. Some electric heaters have a temperature dial, but most don't so you’ll need to use trial and error to find the right thermostat setting.
- Check that the temperature sensor for the thermostat is located far away from the hot parts of the heater - for example at the bottom of the heater where the unheated room air is drawn in. Otherwise, the heater itself interferes with the temperature sensor and you can end up with large temperature fluctuations.
- If the thermostat of your heater doesn't work very well, use a separate plug-in thermostat. You can buy them online. Or you can get an electrician to install a separate, hard-wired room thermostat. They’re usually wall-mounted and, if installed correctly, are better at sensing the actual room temperature.
Timers allow you to turn on a heater to warm up the kitchen half an hour before getting up, or turn a heater off after you have gone to bed.
Fans help to warm up rooms faster by distributing heated air evenly rather than letting heat build-up near the ceiling.
Some heaters have a built-in thermal cutout, which turns the heater off if it overheats - this is an important safety feature to look for.
Some portable heaters have a built-in tilt switch, which turns the heater off if the heater overturns - another important safety feature to look for.
The table below shows how much electric heaters of different wattages cost to run, assuming an electricity price of 25 cents/kWh. The heater wattage is generally specified on a heater’s packaging, in the instruction manual and on a label on the heater itself. If your heater has a few different heat settings, refer to the heater’s instruction manual for the wattage of each setting. Note that the running costs in the table ignore the heater’s thermostat. If the thermostat turns the heater off for some of the time, then running costs per hour will effectively be lower.
|Heater Wattage||Electricity Costs|
|250 W||6 cents/hour|
|500 W||13 cents/hour|
|1000 W||25 cents/hour|
|1500 W||38 cents/hour|
|2000 W||50 cents/hour|
|2400 W||60 cents/hour|
- Safety first - always follow the manufacturer's instructions to avoid electrocution, burns and fire. Keep your heater well away from things that could catch fire, and never cover your heater. Replace your heater if it has broken parts, makes funny noises or smells. Only use one heater per power outlet to avoid overloading.
- Position convection, oil column or micathermic heaters on the cold side of the room - for example, near a window if possible. Heated air will mix with the cold downdraught from the window, resulting in better heat distribution and greater comfort. For your safety, keep the heater well away from curtains.
- Only heat the areas you're using - and only while you're using them.
- Keep the heat in - by shutting doors and curtains.
- Set the thermostat for healthy indoor temperatures - aim for 18°C to 20°C, and 16°C in bedrooms overnight. High thermostat settings cause high heating costs.