A Guide to Storage Heaters in the UK

Storage heaters recharge at night and only produce heat during the day

They are best suited for homes on two-rate tariffs, such as Economy 7

Storage heaters cost from £100 for basic models, up to £700 for advanced ones

With gas boiler installations currently being phased out of UK homes, many households are turning to alternative heating methods, such as electric boilers and heat pumps, to keep their properties warm.

Storage heaters are another option homeowners can look into. Although many won’t have heard of them, storage heaters have actually been around for a while – over 70 years, in fact.

The technology has improved a lot over the decades too, with modern storage heaters now being more energy efficient than past models, and having better temperature regulating functions.

So, are storage heaters a good option for you? In this article, we’ll take you through exactly what storage heaters are, how they work, how energy efficient they are, and whether they are worth it.

storage heater attached to wall in house

What is a storage heater?

A storage heater is a device that generates heat overnight using electricity. It then stores this heat and uses it to warm the home during the following day.

This heating system is designed for households that don’t have access to a gas supply, and are on a two-rate electricity tariff, such as Economy 7.

These tariffs offer cheaper electricity rates, but the exact amount you’ll pay depends on when you use it. For example, these plans typically offer cheaper electricity during off-peak hours, which usually run from 11pm to 8am.

As for aesthetics, storage heaters look similar to radiators. However, unlike radiators, they won’t be able to heat the property at any time of the day.

One of the downsides to having a storage heater is that it won’t heat your home during the nighttime, since this is when it recharges. And once the stored heat runs out in the day, it won’t be able to produce any more heat – after all, it can only store a set amount of energy each night.

That said, a few storage heater models have a booster function, which you can use if you run out of stored heat or if you need more warmth. Using this function will increase the running cost though, since you’ll be using peak-hour electricity.

How do storage heaters work?

Storage heaters draw electricity from the grid overnight. They then store this electricity as thermal energy in clay or ceramic bricks that are fitted inside the heater.

During the day, storage heaters take in cold air from the property, heat it with the stored thermal energy, and release it back into the room.

The stored heat then spreads the heat around the room using convection currents to make sure the temperature is even throughout the room. A lot of newer models are also fitted with quiet fans that can help disperse heat better throughout a room.

Storage heaters can be broken up into two categories, manual and automatic, which we’ve explained below.

Manual storage heaters

Most manual storage heaters are older models. They often have two dials – one for ‘input’ and one for ‘output’.

The ‘input’ dial controls how much heat you store overnight – the higher the setting, the more heat you store. The ‘output’ dial, on the other hand, controls how quickly heat is released throughout the day. So if you keep it on a high setting, your room will warm up quickly, but you might run out of heat by the evening.

Automatic storage heaters

Most modern storage heaters are automatic models. They usually have built-in thermostats and digital programmers, which means that you can preset the input and output settings. This saves you from constantly having to adjust the settings throughout the day.

They also often have silent fans, unlike older units. Some models can also auto-adjust how much energy they store overnight and how much heat they release, based on the room’s temperature, making them much more energy efficient than older heaters.

How to use storage heaters efficiently

To use storage heaters efficiently, you should make sure you’re on a two-rate electricity tariff, such as Economy 7 or Economy 10, which will allow you to get cheaper electricity rates at night.

During colder months, turn the input setting to high, so your heater can store the maximum amount of heat during the night. In the morning, you should also turn the output setting to high if you want to quickly heat your home, and then turn it to low during the rest of the day, so the heat is released gradually.

It’s worth noting that you shouldn’t keep your storage heater on high, otherwise you might run out of energy before the end of the day.

When the weather gets a little warmer, you should decrease the input to medium or low, since you won’t need to store as much energy to heat your home.

During summer, or when you’re away for a long period of time, switch your storage heater off to make sure you aren’t paying unnecessary bills.

Finally, it’s worth getting a modern automatic storage heater, which are much more efficient than manual ones because of their self-regulating features.

You won’t have to worry about adjusting the controls multiple times a day, and you’ll waste less energy, which will save you money on your electricity bill.

Automatic storage heater installed next to wall in house

How much does a storage heater cost?

Storage heaters vary in price, with basic manual models costing around £100, and more advanced models costing between £350 and £700.

However, bear in mind that you’ll need at least one heater for each room. This means it would cost around £2,800 to buy enough modern automatic storage heaters to heat a three-bedroom house.

Storage heaters that come with advanced features, such as temperature sensors, are usually more expensive. But they will also generally be more energy efficient, which means they’ll cost less to run.

There are also some additional costs to take into account. For example, it costs around £1,000 to install a new storage heater system, and around £100 to replace an existing storage heater with a new one.

Although it’ll save you money, you shouldn’t install a storage heater yourself, unless you’re a trained electrician, because they need to be wired into the wall.

Are storage heaters expensive to run?

Storage heaters can be expensive to run if you’re not on a two-rate tariff, which lets you benefit from cheaper electricity rates at night.

A 1.5 kilowatt (kW) storage heater costs 30p per hour to run on a standard off-peak electricity rate of 20p per kilowatt hour (kWh). That means it’ll cost around £2.10 per day to run if you’re charging your storage heater for seven hours each night.

If you’re not on a two-rate tariff, it’ll cost around £3.57 per day to run a storage heater on a standard electricity rate of 34p per kWh.

Keep in mind that the daily running cost will be higher if you want to heat your entire home using storage heaters, since you’ll need at least one unit in each room. It would cost around £12.60 per day to heat a three bedroom house on a two-rate tariff, if you’re charging your storage heater for seven hours.

Are storage heaters cheaper to run than gas boilers?

If you are heating your entire house, having multiple storage heaters will be more expensive to run than a gas boiler system. That’s because electricity is currently more expensive than gas, even with off-peak rates.

Gas currently costs around 10.3 p per kWh, whereas off-peak electricity costs around 20p per kilowatt per hour. This doesn’t mean that storage heaters are twice as expensive to run though, because gas boilers typically use more kWh than storage heaters to produce the same amount of heat.

The average three-bedroom house needs a 27 kW gas boiler – and because boilers also heat water for your showers and taps, you’ll use it all year-round.

Storage heaters, on the other hand, typically come in a  1.5 kW size. You’ll also probably turn them off in the summer, since you’ll only use them to heat your home, not your water.

You can also minimise the running cost of storage heaters by opting for high heat retention storage heaters, which are around 27% cheaper to run, according to the Center for Sustainable Energy.

Are storage heaters eco-friendly?

Storage heaters are somewhat eco-friendly because electricity is less carbon intensive than gas. However, only 38.2% of the UK’s electricity is currently generated by renewable sources, with fossil fuels, imports, and nuclear power making up the rest.

This means that appliances that consume this electricity are not yet 100% eco-friendly.

Storage heaters can become more eco-friendly if you’re on a green tariff, which only provides electricity from renewable sources. Homeowners can also install solar panels to power their storage heaters with clean electricity.

Want to find out how much this would cost you? Visit our page on solar panel costs.

The main problem with storage heaters is that they aren’t as energy efficient as other forms of electric heating, such as heat pumps. The most efficient storage heaters have an energy efficiency of 100%, compared to a heat pump’s average efficiency rating of 300%.

Energy efficiency is important if you’re trying to be eco-friendly, since less energy being consumed means fewer carbon emissions.

To make sure energy isn’t being wasted when using a storage heater, make sure you get one that is compliant with Lot20 – a piece of legislation that outlines energy efficiency requirements for newly manufactured storage heaters.

The most important factor is that storage heaters need to have a minimum energy efficiency rating of 38% for a heat output above 250 watts (W).

In practice, this means new storage heaters now have features that optimise energy usage, such as digital programmers, open window sensors, electronic room temperature controls, adaptive starts, fans, and WiFi control.

Should you get a storage heater?

If you’re currently on a two-rate electricity tariff, it might be worth looking into storage heaters – especially if you have solar panels on your roof to power them.

However, if you’re on a standard  electricity rate, it won’t be financially beneficial to switch to storage heaters

Storage heaters don’t offer much flexibility in terms of when you get to heat your home, and can’t fully replace a gas boiler, since they don’t provide hot water for showers and taps.

This means if you want to use storage heaters as an alternative to a gas boiler, you’ll have to install a separate system to get hot water, such as an electric hot water tank, which costs around £875.

If you’re looking for alternative ways to heat your home and your water, you might want to consider other options, such as electric boilers or air source heat pumps, before you make your final decision.

These appliances will save you from having to install two separate systems for your heating and your hot water – although, you’ll still need to install a hot water cylinder. They’re also usually more energy efficient than storage heaters, which means they cost less to run.

It’s also worth noting that some energy suppliers are phasing out tariffs like Economy 7 that make using storage heaters economical.

For context, around 1.7 million households in the UK have storage heaters, but most of these are old models that are not energy efficient.

Next steps

All in all, storage heaters are definitely a more eco-friendly way to heat your home than gas boilers. However, they can be more expensive to use, even with cheap off-peak electricity rates, and they aren’t as energy efficient as other heating systems.

If you think storage heaters aren’t right for you,  a great alternative option  is an air source heat pump. The government is even offering grants to help UK households switch from gas boilers to heat pumps, through its Boiler Upgrade Scheme.

Frequently asked questions

Storage heaters can be cheaper to run than electric radiators if you are on a two-rate electricity tariff, such as Economy 7. However, if you’re on a regular tariff, then using an energy-efficient electric radiator will typically be cheaper to run. It’ll also give you the flexibility to choose exactly when you heat your house.

Running costs will depend on the wattage of the radiator and the energy efficiency rating of each device, so be sure to check these.

High heat retention storage heaters are the most energy efficient option. They’re better insulated, which means the ceramic bricks inside the unit will stay warmer for longer, and the unit will stay cooler when it is not in use.

Heat pumps usually offer a better way of heating your home compared to storage heaters. Heat pumps can warm both your property and water for washing – not to mention they can provide heat at any time of the day and night, unlike storage heaters.

Heat pumps are also more energy efficient, which means they work out cheaper to run. They typically have an efficiency rating of 300%, whereas storage heaters have an efficiency rating of 100% at most.

Once they’re fully charged, storage heaters usually have enough heat to last roughly 12 hours – but they will run out of heat throughout the day.

If you have your output on high, you’ll lose warmth faster and won’t have enough to heat your home in the evening. That’s why it’s best to leave your output on low, so the heat is released gradually throughout the day.

Written by:
Tatiana has written about multiple environmental topics, including heat pumps, energy-efficient household products, and solar panels. She is dedicated to demystifying green tech to make eco-friendly living more accessible.
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