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Electric heaters: types of plugin heater, costs & what's best for you?

The headlines

ALL (yes, I mean ALL) electric heaters are basically 100% efficient.

Electric heaters are the MOST expensive way of directly generating heat.

There are several types of plugin electric heater. How each type is used will make a big difference to both your costs and comfort.

This article explains the different types and what they are best used for, so you can work out which is the most suitable one to help you keep your costs down.

There are some useful and creative tips at the bottom, so do scroll down.

This article does not talk about storage heaters. I shall be writing a separate article on those in the near future.

If you want to skip the explanation, just skip to the Tips section at the bottom

For very important safety information on using electric heaters see here.

I don't talk about storage heaters in this article but hope to post an article on these in the months ahead.


So how efficient ARE electric heaters?

There are adverts galore for electric room heaters that claim to be 'incredibly efficient' or the 'most efficient', and the best for saving you money.

Some even claim they are 100% efficient.

Sounds great!

But the truth is, when it comes to converting electricity into heat:

  • ALL oil or fluid-filled radiators are 100% efficient

  • ALL electric convector heaters are 100% efficient

  • ALL fan heaters (including ceramic) are 100% efficient

  • ALL halogen/infrared heaters are 98-99% efficient. (If it weren't for the fact that a tiny amount of the electricity is used for their orange light, they would be 100% too!)

Even though electric heaters ARE so efficient, the cost of a unit of electricity is more than three times the cost of a unit of gas. At prices in October 2023, a 3kW portable fan heater will use around 80 pence in electricity if left on full for one hour.

That's expensive.

The only difference between them all is the WAY they give their heat out and how they are controlled.

So one will suit your needs best?

As they vary so greatly in the way they give out their heat having the right type heater for your needs often makes a big difference in how much they will cost you to run.

The table below gives you a summary of the pros and cons of each type, and my thoughts as to where they are each best used.

Heater type

Best suited to



Oil-filled portable

Heating a whole room up where it doesn't matter that it is a little slow to get going. So, better suited to when you want the room to be warm for longer periods.

Maintain a pretty steady room temperature. All have a thermostat to help you avoid overheating a room. Some have timers built in.

Quite slow to get going. Heavier and bulkier than other types of portable heater.

Convector heater (portable or sometimes wall- mounted)

Heating a whole room up fairly quickly, but where you don't mind the temperature going up and down a little. A good option if you want a room heated for medium-long periods.

Warm up a room quite fast, and more quickly than oil-filled heaters. Lighter than oil-filled heaters. All have a thermostat to help you avoid overheating a room. Some have timers built in.

Don't control room room temperature level quite as evenly as oil-filled. Rarely, if ever, have timers built in.

Fan and ceramic heaters

Warming a whole room really quickly, if you don't mind the noise and the 'all or nothing' heat they put out. A good option if you really only want the room to be warm for shorter lengths of time or a quick blast in a cold bedroom before you get up.

Warm up a room very quickly. Heat can be directed to a specific part of the room, if needed. Always have thermostats. The smallest of all heater types.

Noisy. Heat from these feels like it is ALL or nothing, and the room temperature will swing up and down more than with other types of heater.

Halogen heaters

Heating people directly rather than for heating a room. Think of these as a heat ray for warming objects. A room will warm up eventually, but they give priority to heating YOU first, which is often the most important thing.

They use infrared heat which is directional very effective at heating objects (including people!) really quickly and with high levels of comfort. The air in the room won't feel as dry using this type of heater.They usually have a low power setting (400 Watts) which, if just heating one or two people, is lots!

You need to put them close to you to keep warm so need to be careful of the hot surfaces. Probably unsuitable to be used around small children. No built-in thermostat or timer. Some people believe there are health issues from the glare of these if you are too close to them or face directly into them but I can find no reliable expert information on this online.

Here is further information about each type of heater and how they work.


Oil-filled radiators

They have a fluid inside which is heated first before releasing a noticeable amount of heat into a room. As it is heated up, the whole heater body warms up, just like a central heating radiator. This warmth rises, then slowly circulates around the room.

They provide a slow and steady type of heat and are pretty good at keeping the room temperature quite stable.

Once they get to the temperature you have set, the heater automatically switches off and on to maintain this temperature. As it does this, you can usually hear the internal heater 'clicking'.

How powerful an oil filled radiator is DOES NOT affect how much it costs to run it. A more powerful one (or one with multiple settings and the switches set to the highest setting) will mean your room will warm up more quickly.

Once the room is at the temperature you set the thermostat at, it will cost the same amount to run PER HOUR regardless of what settings the switches are at. If you like the room at 20C then it will use the same amount of energy to keep the room at 20C regardless of the power switch settings.

The way to keep control of costs using one of these is careful use of the thermostat!

The running cost per hour will vary depending on how big the room is, how well insulated it is, and what temperature you set the thermostat to.

Once you have got the room to a temperature you like, why not put a mark on the thermostat at the position to set it as a "favourite" position for next time.


Convector heaters

These are mostly portable, but are sometimes wall-mounted.

These just heat the air inside the casing, which then rises quickly and gradually spreads around the room, warming it up. They emit higher temperature air than oil filled radiators so you will feel the effects of them more quickly.

They are lighter and easier to move than oil-filled radiators.

They always have a thermostat to control the temperature but won't keep the temperature in the room quite as consistent as an oil-filled radiator.

Like oil filled radiators these

  • Often have different power switch settings that just affect how quickly the room warms up

  • The cost per hour to run them will be directly affected by the temperature you want the room at, which is set by the thermostat. The larger the room is or the more poorly insulated it is, the more it will cost to run per hour.

Fan heaters (including ceramic heaters)

These are usually physically smallest types of heaters. They heat the air inside the unit which is then blown into a room at a fixed speed.

They have the benefit of being directional but feel a little all or nothing when being used.

They always have an adjustable thermostat so they switch on and and off automatically to keep the room at a temperature that you set on the thermostat. Like the heaters above, the setting you have the thermostat at will directly affect the cost to run one of these (the warmer the room the more it will cost).

Depending on where you put them in a room, the room temperature probably won't be controlled as evenly as using oil-filled radiators or convector heaters. So, they feel a bit "all or nothing" and they can be quite expensive to run as some people like to feel the heat from them "continually" which means the room will end up warmer than you really need it = wasting money.

'Ceramic' fan heaters

There are very small plug-in fan heaters currently advertised on the market (often calling themselves PTC or ceramic heaters), such as this one.

These are basically just very small fan heaters with around half the heat output of the lowest setting on a normal fan heater. They are just as efficient as all other electric heaters, 100%.


Halogen heaters (sometimes called infrared heaters)

Infrared heat is the sort of heat we are all familiar with near a bonfire or fireplace, which you can always feel instantly.

I like to think of the heat from these as a directional heat ray that provide instant very cozy feeling heat. They heat objects near them (such as humans!), and don't really heat the air directly.

By FAR the most effective way to use them is to put them near you and facing towards you so that they warm YOU up, and not the room.

The fronts do get quite hot though so caution is needed.

They are NOT so well-suited to heating the WHOLE room, if that is what you want to do. They WILL warm a room up but heat from them will be absorbed by objects in the room first (such as humans!).

They also don’t normally have thermostats, so you can’t set them to keep a room at a fixed temperature. However, they do usually have a very low output setting (generally 400 Watts), which even on that setting I find loads if it is quite close to me.

The lowest 400 Watt setting costs around 11p an hour to run assuming a standard tariff from Oct 2023.


  • Given how expensive using electric heaters is, as I've said above, using a thermostat if a heater has it is really important to make sure it doesn't overheat the room unnecessarily and waste money. The photos further down give some very useful visual tips.

  • To keep heat in, always keep doors shut. This is most particularly important with oil-filled, convector and fan heaters as they directly heat the air in the room, so thermostats will work better with doors shut.

  • If you want to work in a cold garage or workshop, halogen heaters, in my experience, are the most economical way of keeping warm if they can be positioned in a good and safe place. In my garage I have one that just heats 'me' rather than trying to heat my whole garage (which would cost a fortune!). I used to use a portable gas heater, but find the halogen heater is far better.

  • Look out for another article soon about the challenges of working from home, to help you decide whether it is best to have the heating on during the day or use an electric heater of some sort in the room you want to use.

  • If you need to use electric heaters regularly, one of these low cost energy monitoring smart plugs is a fantastic way of keeping track of how much energy your heater uses and costs.

  • If you use a smart plug and have a smartphone, you can set up a timer on your phone to control an electric heater, either to pre-warm a room or make sure it isn't on when you don't want it on.

  • If a heater has a thermostat on it, turning the dial up really high won't make the room warm up any quicker. It will just mean it overheats.

  • It is best to make small adjustments on the thermostat up or down if you are too warm or cool.

  • Thermostats on heaters very rarely show a temperature scales in degrees C. Below are some practical suggestions on how you can do something about this, and avoid overheating rooms and wasting energy.

Not everyone agrees on what temperature they want a room.... This first idea is one (fun) way of labelling a heater thermostat to avoid arguments.....

If you have a thermometer, you can gradually work out which thermostat position works best for you in a particular room.

My fan heater shown here is a 2kW output heater, so the highest heater setting is 2kW and the lower setting is 1kW.

If it runs CONSTANTLY for an hour the cost of running it works out at up to 54p an hour at the high setting per hour or 27p an hour on the lowest setting.

Labelling these costs on the thermostat of a heater could also be a way of helping control costs.

If you have a 3kW heater, your highest output will cost you 80 pence an hour if it runs constantly!

Below is the labelling on my halogen heater, showing the cost per hour running it for the different heat settings. Each switch cranks up the output in different stages, so with all three switches flicked it costs 33p an hour to run.


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If you have any other suggestions for additions or changes to site content do please let me know. While I have made every effort to ensure that the information contained on this website is correct, I cannot take responsibility for errors or omissions.

All content on the site should be treated as information and not advice. You should take professional advice where appropriate to different site articles.


Mark Thompson

Get Energy Savvy - simple practical home energy efficiency information

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1 Comment

May 22

As an HVAC Contractor, I recommend using thermostats on electric heaters to prevent overheating and save money. Keep doors shut to retain heat, especially with oil-filled, convector, and fan heaters. For garages, halogen heaters are economical. Smart plugs can monitor energy use effectively.

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