How Do Storage Heaters Work?

That's where storage heaters come in. Designed to work with off-peak energy tariffs, they help keep your home warm without breaking the bank.

But what exactly are storage heaters, and how do they work?

What is a storage heater?

Storage heaters, also known as 'night storage heaters', are a type of electric heating system designed to take advantage of off-peak energy tariffs like Economy 7 and Economy 10. Instead of using electricity throughout the day, they charge up overnight when rates are lower, storing heat in ceramic or clay bricks, or other modern materials like gel. This heat is then gradually released during the day to keep your home warm.

While storage heaters aren't as common as they used to be, they're still a popular option for homes without a gas supply. They offer a more energy-efficient alternative to standard electric radiators.

Types of storage heater

You may not have realised that storage heaters come in various types that work slightly differently. Finding the right model for your home depends on your heating needs, your energy tariff, and how much control you want over the temperature settings.

Here are the most common storage heater types:

How do storage heaters work?

The way your storage heater works depends on the type of model you have and whether you're using a standard or time-of-use tariff. But in general, they all follow the same basic process:

1. Charging during off-peak hours — They use cheaper night-time electricity to heat an internal element that warms the materials stored inside the unit.

2. Storing heat efficiently — These materials are surrounded by insulation, helping to store the heat so it can be slowly released throughout the day.

3. Releasing heat throughout your home — Depending on the heater model, you can adjust how much heat is released and when.

Let's break it down further:

Economy 7 storage heaters

If you're on an Economy 7 tariff, your electricity is automatically cheaper during off-peak hours (usually between midnight and 7am). Storage heaters are designed to charge up overnight, meaning they'll take advantage of these more affordable rates.

On an Economy 7 tariff, a storage heater:

• Stores heat when electricity is cheapest and releases it when needed, making itthem more cost-effective than regular electric radiators.

• You can control when and how much heat is released using the output settings on your heater.

• Some modern models also have 'intelligent charging', which adjusts the storage levels based on your home's heating needs.

For more information, see our guide to Economy 7 tariffs.

Standard tariff storage heaters

Storage heaters are designed to work with time-of-use tariffs, so it's rare that you'll have them installed if you're on a single-rate tariff. However, if you do, your storage heater will work similarly to traditional electric heaters but with a key difference: it stores heat rather than generating it on demand.

The heater will still power on overnight and hold onto the heat throughout the day, but you won't benefit from the cheaper off-peak prices — which can make storage heaters more costly than standard electric radiators.

5 Benefits of using storage heaters

Storage heaters can be a great option for keeping your home warm if you don't have access to a traditional gas central heating system — but there's more to them than meets the eye. Here are some of the other key benefits of installing one in your home:

1. Lower energy bills

Many people automatically assume that all electric heating is expensive, but storage heaters are specifically designed to be more economical.

They use off-peak electricity unit rates (which are cheaper than daytime rates if you're on an Economy 7 tariff) to store heat, making them a cost-effective alternative to standard electric radiators. Plus, upgrading to a modern storage heater model with a thermostat and timer could potentially save you up to 10% on your energy bill.

2. Adjustable temperatures

Most modern storage heaters have adjustable thermostats, letting you control how much heat is released throughout the day. This means you won't waste stored heat by overheating your space and needing to crack a window open, but you can still stay warm when temperatures really drop.

3. Quiet to use

Unlike fan or oil-filled heating systems, storage heaters are almost silent — even fan-assisted models are designed to run with minimal noise. This makes them ideal for bedrooms, home offices, or any other space where you typically don't want disruptive background noise.

4. Simple installation process

Storage heaters are quick and easy to install. With no pipes or boilers involved, there's no need for complex plumbing work — they simply need to be wall-mounted and wired into your home's electrical system.

5. User safety

Storage heaters are one of the safest heating options available; because they don't burn fuel or produce carbon monoxide, there's no risk of gas leaks or harmful emissions. There's also no need to book regular services — making them a low-maintenance way to heat your home.

Are storage heaters expensive to run?

Storage heaters aren't necessarily expensive to run, but since they use electricity, which tends to cost more per unit than gas, they can be pricier than traditional gas central heating.

However, because they're designed to store and release heat efficiently, they can still be a cost-effective choice — especially if used with an Economy 7 tariff.

That said, the cost of running a storage heater depends on its age and design.

Modern storage heaters

Newer storage heaters are built with better insulation, thermostat controls, and programmable timers, making them far more energy-efficient than older models.

Here are some other cost-saving benefits to consider:

• They can store and release heat more effectively, reducing waste.

• Many have automatic temperature adjustments to avoid overheating.

• Some models even have WiFi connectivity, letting you control settings remotely. They can even consider future weather forecasts and estimate whether heating needs to be adjusted based on the predicted temperature.

Old storage heaters

Old storage heaters can be more expensive to run because:

• Some older models release heat continuously, even when it's not needed, which can lead to overheated rooms and wasted electricity.

• Many lack programmable controls, meaning you have to manually adjust settings, which isn't always convenient.

• Older units may not be as well insulated, meaning they lose stored heat more quickly.

If you have an older storage heater, upgrading to a new model may save you money in the long run.

How to use a storage heater correctly

Storage heaters sometimes get a bad reputation for being tricky to use, but once you know how they work, they're surprisingly straightforward.

Most models have two main controls:

• Input — This controls how much heat is stored overnight.

• Output — This controls how quickly the stored heat is released.

Setting up your storage heater controls

The right settings will vary depending on the weather and how much heat you need. Here's how to adjust them properly:

• On cold days — Turn the input up high overnight so the heater stores more warmth. During the day, adjust the output so you don't lose all the heat too quickly.

• On milder days — Lower the input setting to store less heat, saving electricity. Keep the output on a low setting so heat is released gradually.

• When you don't need heating — Turn the input down or switch the heater off at the wall to stop it from powering on and storing heat unnecessarily.

Always check your user manual. If you have a newer storage heater, it may have an inbuilt thermostat or automatic controls, so you won't need to change these settings manually.

Tips for using your storage heater

To get the most out of your storage heater and avoid wasting energy, follow these handy tips:

1. Check your energy tariff — Storage heaters are designed for time-of-use tariffs and can be more expensive than regular electric heaters if you're on a single rate. If you're unsure which plan you're on, check with your energy supplier to ensure you're getting cheaper off-peak rates.

2. Avoid covering the heater — While it can be tempting to use the heater to dry your washing, never place wet clothes or furniture too close to your storage heater. This can be a fire hazard and block the heat from spreading properly.

3. Leave space around the heater — Keep any furniture at least 30cm away so heat can circulate freely. If you have a window above the heater, make sure the curtains are at least 7.5cm away to prevent overheating.

4. Use the controls efficiently — If your heater has manual controls, adjust the input and output settings based on the weather. For automatic models, set the thermostat to a comfortable temperature and let it do the work for you.

5. Consider using a heater guard — If you have small children or pets at home, fitting a heater guard can help prevent accidental burns, as storage heaters can get hot to the touch.

Explore storage heater-friendly tariffs with UW

Storage heaters can be a great way to keep your home warm when used with the right energy tariff.

At UW, we offer a wide range of energy deals to help you save on your electric, or if you’re looking for a new gas tariff, we’ve got you covered.