Storage heaters explained

Storage heaters mean you can take advantage of lower off-peak electricity rates to heat your home.

They are part of an electric heating system and you'll need a time-of-use tariff (such as Economy 7 or Economy 10) to access cheaper electricity prices.

Keep reading to find out how storage heaters work, how much they cost, and the savings they could generate for you.

How do storage heaters work?

Storage heaters store heat generated from cheap night time electricity and release it during the day.

They use electricity to heat up ceramic or clay bricks inside them overnight and release the heat gradually to keep your home warm the next day.

Night storage heaters are designed primarily for homes with time-of-use electricity tariffs, such as Economy 7 or Economy 10. These have cheaper rates for electricity overnight (around 12pm-7am but times vary). This means you can use cheaper off-peak electricity to heat your home during the day.

Find out more about the different types of energy tariffs, including Economy 7 or Economy 10 tariffs, with our guide.

How much do storage heaters cost?

Storage heaters vary drastically in price, depending on the type and brand you choose. Basic models start at around £150 but modern ones can cost upwards of £400. 

More expensive storage heaters tend to be more efficient, and therefore cost less to run. 

Installing a replacement storage heater usually costs from about £70 if there is existing wiring, but it will be pricier if it's a new installation or you need new wiring. Prices vary by location.

Storage heaters must be installed by a qualified electrician. We recommend you get at least three quotes because prices vary. 

Find a recommended electrician who has been through our rigorous checks by visiting Which? Trusted Traders or using our search tool below.

Are storage heaters expensive to run?

Even at off-peak rates, electricity is more expensive than gas, so storage heaters are only really cost effective if you don't have mains gas. 

It can cost around £70 a month to run a 1.4kW storage heater. That's based on charging it for seven hours overnight at off-peak rates.* You won't need to charge it for as many hours in the warmer months.

Bear in mind that you'll probably have more than one storage heater to power. 

Using your storage heater's boost function adds to heating costs because it uses pricier daytime electricity, rather than stored heat.

* Based on 23p/kWh – the cost of Bulb's Economy 7 tariff off-peak in October 2022.

Types of electric storage heater

There used to be five main types of storage heater, which varied by the level of control, energy efficiency and price.

However, from 1 January 2018, all newly manufactured storage heaters must have certain features so that they comply with Lot20, which is part of the European Ecodesign Directive. This essentially means that all storage heaters you can buy now work in the same way.

New electric storage heaters must have a minimum energy efficiency rating of 38% for a heat output above 250W. To meet this, they will often have:

• digital programmers
• open window sensors
• electronic room temperature controls
• wi-fi controls.

Generally speaking, the more you spend on a storage heater, the more features you'll get. 

Most modern models have built-in thermostats and many also have ‘fan-assist’ to help spread the heat around your home. Also look out for high-heat retention casing and ‘intelligent charge’.

If you've had storage heaters in your home for a while, they might be one of the following:

• Manual storage heaters – the cheapest and most basic. They store energy at night and release heat automatically during the day. They continue running unless you switch them off.
• Automatic combination – these combine a storage heater and traditional electric convection heater. You can use the convection heater at any time for an instant boost of heat. They were usually installed in larger rooms where a storage heater alone was insufficient.

Storage heater features

Common useful storage heater features include:

• boost function: some storage heaters have a boost function to give you extra warmth when you need it
• fan assist: a number of storage heaters, usually auto-combination models, include a silent fan that helps to dispel heat more efficiently 
• programmable heating schedules: newer storage heaters should have controls to let you set customised heating patterns for different days and times, just as you would with gas central heating
• size: if your room is large, or not very energy efficient, you may need a larger storage heater to warm it effectively
• thermostatic controls: new heaters have thermostatic controls, which will get the room heated to your chosen temperature
• remote controls: some models can be controlled via remote or from your smart phone over wi-fi.

Manual storage heaters are the cheapest to buy, but are very basic and don’t allow much control over the heat output. This can lead to wasted energy and overheated rooms. 

Because of this, manual storage heaters are gradually being phased out and replaced by more efficient, automatic models. An automatic storage heater will save you money in the long run, but usually cost more upfront.

Pros and cons of storage heaters

Pros

• Cheaper to run compared with other types of electric heating that rely on peak-rate electricity.
• Modern storage heaters can release heat as needed, depending on the external temperature, which should help save on your bills.
• Storage heaters are very quiet, even if they have a fan.
• They're easy to install and can go anywhere that it's possible to wire them in.

Cons

• Usually pricier than gas heating.
• Basic models can overheat rooms when they release excess heat.
• Your home might be coldest in the evening because the storage heater has often released most of its stored heat by then.

Need an extra burst of heat? We reveal the best electric heaters.

Storage heaters and solar panels

If you have solar panels, you could use the electricity they generate to charge your storage heaters during the day so you still have warmth in the evening.

Find out more about solar panels.

Asbestos in storage heaters

Some older storage heaters, typically those produced before 1974, used asbestos to reduce the risk of fire. If damaged, they may release asbestos dust and fibres. 

Breathing this in can cause damage to your lungs and contribute to a range of cancers. 

If you have an old storage heater in your home and are concerned that it contains asbestos, contact the manufacturer to find out. 

If you discover that your storage heater contains asbestos, contact your local council to organise the heater’s safe removal.