What is the most cost effective heater?

It’s important to be conscious about our energy usage - it helps us look after both the planet and our bills.

According to the Government’s annual domestic energy bill report, the average UK electricity bill across all payment types rose by £391 to £1,160 in 2022! While costs have since decreased, they still remain higher than pre-pandemic levels, making it crucial to stay mindful of our energy spending.

When the cold weather closes in during Autumn and Winter, it’s easy to get carried away with exactly how much electricity we are using, especially when it comes to heating your home.

Electric heaters (or space heaters) are a great way to heat individual rooms in your home. This means you don’t always have to fire up the central heating if you’re feeling chilly, which often ends up wasting energy by heating up rooms that you’re not using!

However, there are a number of different types of electric heaters on the market, which makes it difficult to know which type of electric heater is best suited to your requirements and which are more energy efficient than others.

If you’re looking for energy efficient heaters to warm up your home, or if you’re doing some research ahead of purchasing a new electric heater, here is a breakdown of each type of electric heater. We’ll run through what they’re good for, and how much they will cost you to run.

How to calculate energy efficiency

We’ve calculated these costs based on the average electricity prices for England, Scotland & Wales following Ofgem's Price Cap, valid from 1st April 2026. The cost of electricity is measured in kWh (kilowatts per hour) for a standard rate and is currently 24.67p per kWh. The rates for Economy 7 energy therefore may differ, but will hopefully still give you an idea of which types of room heaters have the cheapest running costs.

To calculate the electricity cost of running an appliance, follow these simple steps:

Find the power of the appliance in kilowatts (kW): To do this, divide the wattage by 1,000. For example, a 1500W appliance equals 1.5 kW.

Multiply the kW by the number of hours the appliance is used: For instance, using a 1.5 kW appliance for 1 hour = 1.5 kWh of energy used.

Multiply the result by the electricity rate per kWh (24.67 pence as of Apr 1st, 2026). For example, running a 1.5 kW appliance for 1 hour costs:

1.5kWh x 24.67 pence = approx. 37.01 pence per hour

Halogen Heaters

Halogen Heaters are great for instant heat. They get their name from the halogen element inside the bulb or lamp of the heater which, when combined with electricity, heats up and provides a radiant heat.

The radiant heat means halogen heaters will heat up the area directly in-front of them, which is great if you want a quick blast of heat but not so much if you are looking to heat a whole room equally.

Generally speaking, Halogen heaters are one of the most inexpensive types of electric heater. They average around 1200W in terms of power output and because they provide instant-heat at close quarters, you shouldn’t need to leave them on for long periods of time.

Convector Heaters

Convector heaters are ideal for warming up small to medium sized rooms with even heat distribution. Convection heaters work by circulating air through the room by the process of convection - where warm air rises and cold air sinks. Cold air is sucked into the bottom of the heater and travels along the heating element, where it is warmed and then exits the heater at the top.

The nature of convection heaters mean they usually take a little longer until you feel the heat (compared to a halogen heater for example), but it will heat the whole room evenly. Typically, convection heaters are around 2000W in power output which does make them more expensive to run. On top of this, you might tend to leave a convection heater on for longer periods of time too (compared to radiant heaters). 

However, most convector heaters come with a built-in thermostat control. This means you have control over the heat and power output of the heater, and therefore become more efficient to run.

Oil Filled Radiators

Oil-filled radiators are great for a long lasting heat. They work by heating thermodynamic oil inside the body of the radiator. When switched on, a heating element submerged in the oil heats up. This in-turn heats the oil, which transfers heat to the body of the radiator. As the radiator gets hot, the room is warmed via both convection and heat radiation.

The average wattage on an oil-filled radiator can vary quite a lot, which therefore means how costly they are can vary. However, many oil-filled radiators will come equipped with a built-in thermostatic control, which therefore allows you to control the power and heat output of the radiator. For this reason, they can be considered one of the most energy efficient types of heaters. 

On top of this, oil-filled radiators retain heat much better than other room heaters; meaning heat will still radiate from the radiator for a short while after you’ve switched it off. For purposes of assessing the cost of running an oil-filled radiator, we have assumed the average wattage is 1500W.

Fan Heaters

If you want to warm a small-room quickly, fan heaters are the way to go. Cool air enters the heater at the back, which passes over a heating element, before being blown out at the front via the internal fan.

Because of the nature of fan heaters, the warm air being blown out can reach a further distance more quickly than other heaters, meaning they can quickly heat a room up. 

However, because there is a fan inside, they do produce a noise when working. Fan heaters are generally available for about 2000W, and are often available with thermostatic control.

Conclusion

When it comes to running costs, halogen heaters are usually the most affordable electric heater option due to their lower wattage. 

However, many of the other (more high-watt) heaters come with built-in thermostat controls and sometimes timers, which will allow you to regulate their power output and how long you have them on for. This will help to reduce running costs. Really, it all depends what kind of heater you’re looking for and more importantly how you use it.

It’s also important to note that, if used for over long periods of time, electric room heaters can be expensive to run (as electric is more expensive than gas). They produce quick and intense heat, so should be used intermittently to heat a room up - as opposed to a central heating system which can be left on for longer periods of time.