What is the cheapest heater to run? We take a look at the options

Woman warming hands near electric heater at home
A small portable desktop fan heater is useful for heating a small space (Image credit: Getty Images)

Knowing which is the cheapest heater to run in your home is fast becoming a necessity before investing in one – with electricity bills rocketing up each winter, it is well worth doing the research beforehand.

Fuel poverty charity National Energy Action recently revealed 6.5 million UK households will be in fuel poverty – a rise of two million from two years ago after Ofgem’s price cap change in January. Households are even ‘self-disconnecting’ and going without any energy in their home, going to bed early to save on heating and lighting, and some are even using ovens instead of central heating to stay warm (not something we recommend!).

There are many energy saving tips for householders looking to keep bills lower, but the type of heater they use is a key consideration when considering thermal efficiency. Here we look at the options and see which might be the cheapest.

Heater options

First, let's take a look at some of the main portable heater options available and look at how they work.

1) Halogen heaters

Halogen heaters use halogen gas inside a heating bulb and lamp. They use the light emitted from halogen lamps as a source of radiant heat, instead of conductors, like oil, or heating rods. They are directional and once activated, you instantly feel the heat. As soon as they are turned off, the heat quickly dissipates.

Halogen heater costs vary depending on the wattage and size of the halogen heater you buy, but a decent sized halogen heater can be purchased for around £40 from Argos.

2) Oil-filled radiators

Oil-filled radiators work by using electricity to heat oil with an element inside a reservoir. When the element heats up, the warmth is transferred to the fluid, which then circulates around the appliance and warms its metallic panels. None of the oil is burned as fuel. Oil is used inside the radiator fins rather than water as it retains heat for longer, which is more energy efficient.

Rather than directly heating the person, oil-filled radiators heat air already in the room. When the air gets hotter it rises and shifts the cold air to the floor, where the radiator usually sits. 

Oil-filled radiator running costs are dependent on the model you use. Smaller oil heaters can use as little as 500W of power (possibly less) and are designed to heat smaller rooms, while larger oil heaters can use 2,500W or more. You can now also get 'smart' oil-filled radiators like this Princess model from Argos.

3) Fan heaters

A fan heater is a home heating option that consists of a fan that blows air through a heating element, usually a coil of wire, which converts electricity into heat. This circulates warm air throughout the area. There are many different forms of fan heaters to suit varying needs and these tend to do a good job of heating up a space quickly.

How much it costs to run a fan heater will again depend on the wattage but typically fan heaters themselves are at the lower end of the price scale. This 2,000W Challenge fan heater on Argos is only £17 for instance.

What is the cheapest heater to run?

At a very basic level, the cheapest heater to run will be any heater that has a very low wattage. For example, a 500 watt heater would cost just over 14p per hour under current 28.62p per kWh rates, while a more powerful 2000 watt halogen heater would cost just over 57p per hour.

The calculation for the 500W heater is: 500W/1000 = 0.5, then 0.5 x 28.62 = 14.31p. Meanwhile the 2000W heater calculation is: 2000/1000 = 2, then 2 x 28.62 = 57.24p.

As such, the cheapest heater would be the one with the lowest wattage, rather than the type of heater. However, when choosing the best space heater to buy, there are more factors to consider as lower wattage can also mean lower heat output. 

Homebuilding & Renovating's former Assistant Editor Amy Reeves explains: "The radiant heat of a halogen heater is ideal for warming something, be it a person or sofa, directly, [and so are ideal for open, poorly insulated spaces].

"Oil-filled radiators would be good for smaller [well insulated] rooms as they hold residual heat for longer, meaning less energy is needed to heat the space up. 

"Meanwhile, fan heaters will warm a room up the fastest of all of the space heaters — making them ideal candidates for a quick bust of warmth while your central heating kicks in." 

Therefore, the space you plan to heat should be considered, as well as how long you need to warm it.

Amy Reeves
Amy Reeves

Amy is Homebuilding & Renovating's former assistant editor. She has an interest in sustainable building methods and always has her eye on the latest design ideas and has interviewed countless self builders, renovators and extenders about their experiences.

Are portable heaters cheaper than central heating?

Central heating costs will vary depending on numerous factors such as the size and energy efficiency of your home, the climate where you live, whether you use a heat pump or boiler, when you need heating, how well insulated the property is, and how efficient your boiler is. 

But speaking generally, in your typical household with gas central heating, portable heaters are likely to be more expensive than switching on your central heating. That said, portable heaters can be cheaper, for instance, perhaps when only heating one small room in a large house. Portable heaters are also excellent for heating a space quickly.

How can you save money running portable heaters?

If you're just heating one room either a halogen space heater or oil-filled radiator will do the job well.

The radiant heat of a halogen heater is ideal for warming something like a person or sofa directly. This could be ideal for those working from home in a larger room to combat energy price rises as no energy is wasted raising the temperature of the entire room, simply the material or person that needs it.

Oil-filled radiators would similarly be good for smaller rooms as they hold residual heat for longer, meaning less energy is needed to heat the space up. An oil-filled radiator cost to run could be as little as 20p per hour, depending on the size. Plus, after the first burst of power supply they will gradually radiate heat, keeping the user at a comfortable temperature without being constantly on. 

Sam Webb

Sam is based in Coventry and has been a news reporter for nearly 20 years. His work has featured in the Mirror, The Sun, MailOnline, the Independent, and news outlets throughout the world.  As a copywriter, he has written for clients as diverse as Saint-Gobain, Michelin, Halfords Autocentre, Great British Heating, and Irwin Industrial Tools. During the pandemic, he converted a van into a mini-camper and is currently planning to convert his shed into an office and Star Wars shrine.