Is it cheaper to use an electric heater or gas central heating?

The temperature has dropped again and with snow and ice outside – in parts of the northern hemisphere at least – we’re all searching for heating hacks to save on bills.

Sadly those adverts promising a ‘revolutionary new heating device’ that heats your room in 90 seconds and costs 2p simply aren’t true. But you probably guessed as much already.

The real question, especially if you’re worried about how you’re going to pay your heating bill this winter, is whether to switch on your central heating or to use a plug-in electric heater or two instead.

On the face of it, it can seem like a good idea. You can place the heater next to your desk if you’re working from home, or near the sofa when you’re relaxing in the evenings. As soon as you’re warm, you can switch it off – and you’re less likely to forget and leave it on when it’s right next to you pumping out heat.

There are some situations in which this is a good idea – but plenty more where it will end up costing you more money, rather than saving it.

But rather than simply saying “gas heating is cheaper”, we’re going to show you how to calculate what will be the most effective in your home.

Gas vs electric: which costs more?

We’re assuming here that your home has gas central heating. Most UK homes do. According to a 2022 survey by Statistica, that figure is 78%. And the crucial fact is that gas is much cheaper than electricity.

If you check your energy bills, you can compare the unit price of the two. A unit is one kilowatt-hour. Here are the figures from my bill, which I’ll use as an example:

• Electricity: 35.797p per kWh
• Gas: 10.509p per kWh

So, for me, gas costs less than a third of the price of electricity (29%). And although your figures may be slightly different, the ratios will be similar.

What does an electric heater cost to run?

Using the figures above, we can work out what I’d pay for an hour using a plug-in electric heater. I’ll use the Princess Glass smart panel heater – our best-reviewed portable heater – as an example. It comes in three different versions, with three different wattages: 1,000, 1,500 and 2,000.

For this example, I’m using the 1,500 watt version, as that’s roughly average for an electric heater. To get the most accurate calculation of its running cost, you should plug it into a power meter and run it for an hour.

We explain how to find out how much power any electric device uses if you want to find out what your other appliances cost to run.

But, if you’d just like to get a rough estimate – which won’t take into account the heat setting or fan power – you can use an online calculator and your most recent energy bill. Input your tariff or use a standard one, and fill out the wattage, and the calculator will do the rest.

If you prefer to do it manually, this is the calculation: heater wattage * electricity unit price = cost to run per hour.

As 1000W = 1kW, this means the calculation is 1.5 * 35.797, meaning my 1,500W electric heater will cost me around 54p per hour to run.

The daily standing charges for gas and electricity aren’t relevant here, because those are payable regardless of how much energy you use on any given day.

What does a boiler cost to run?

The next stage is to find out what your boiler costs to run. This is relatively straightforward. You may be able to find it on the boiler itself, or you may need to look up the make and model online.

My boiler is an Alpha CD13R. It’s a 13kW boiler, which means it uses around 13kW of energy per hour, or 13kWh. So, on my 10.509p tariff, it costs me around £1.36 per hour to run my boiler.

The first thing to bear in mind is that I have a small apartment and therefore a small boiler. The chances are that yours will be bigger and will cost more to run. A large house could have a 35-42 kW boiler.

You also need to consider the fact that this is just a rough calculation. It’ll cost you more or less depending on the temperature you set on your thermostat, as well as how many radiators you have, and whether they’re all turned on or not.

Central heating or plug-in heater?

So, for me, using my central heating costs around two and a half times more than one plug-in heater. But the plug-in device will only heat up a small area and the heat will quickly dissipate in a cold house.

To heat my whole home, central heating will be a more cost-effective option. But if you’ve heard the money-saving mantra, heat the person, not the room, you’ll know that’s not always the case.

The cheapest option will depend on how many people are at home and where they are. If you’re alone at home, or all the family is in one room, it may well be cheaper to leave the central heating off and use a plug-in heater to keep everyone warm.

Do some calculations, and you’ll find out for sure.

But here are some other money saving heating tips you can try, too.

Money-saving home heating tips

1. Bleed your radiators

To make your home heating system as efficient as possible, you should bleed your radiators to remove any pockets of air. It’ll cost you less and keep your home warmer.

2. Put reflective backing behind your radiators

Get a roll of backing to put behind your radiators and reflect the heat back into the room. It’s fairly cheap and very easy to do.

3. Move furniture away from the front of radiators

Don’t let any pieces of furniture touch the radiator, as they’ll absorb some of the heat. Where possible move furniture away from radiators altogether, so they don’t block the heat.

4. Turn off radiators in rooms you’re not using

Only switch on radiators in the rooms you’re using. Make sure that radiators in spare bedrooms or an unused dining room are turned off. Switch off the radiator when you leave the bedroom in the morning and switch off the radiator in the sitting room when you come up to bed at night.

5. Invest in smart radiator valves

If you invest in smart radiator valves, you won’t have to go around turning radiators on and off manually. You can schedule heating to come on and off at certain times of the day, so you never waste heat. You’ll also be able to change the temperature from your phone, wherever you are.

Some of these smart thermostatic radiator valves (TRVs) have a digital screen that shows the temperature, so you can see it and set it much more precisely. Many will also be Alexa or Google Home compatible, so you can use voice commands to change the temperature.

The downside is that they are expensive to fit on all your radiators (they cost £45 to £65 each) and are battery-operated, which is an additional running cost. Some also need a compatible hub or smart thermostat to work.

If you already have a smart thermostat, getting compatible smart radiator valves might be a smart move. But if you still have a traditional thermostat / programmer and aren’t sure where to start, we’ve got some ideas.

The Netatmo smart radiator valve starter kit is a solid option. It’s expensive but Netatmo is great quality and there is no subscription costs and you won’t need a separate hub. The kit comes with two valves and a relay. You can buy it direct from Netatmo.

Or, if you’re an iPhone user, there’s an even cheaper option that we’d recommend from another high-quality smart home brand. The Eve smart thermostat is one of the best around. It doesn’t need a bridge or hub, is easy to install and easy to use. You can find out more in our review or buy it from Amazon.

If you’re after a full system, have a look at our round-up of the best smart heating systems we’ve tested. And if you instead want to buy an electric heater, you can find our recommendations and the rundown of the best heaters we’ve tested.