White meter heating explained

For homeowners with electric heating, understanding your system and its future is essential. White meter heating, a legacy system designed to offer cheaper electricity during off-peak hours, is undergoing a significant change with the phase-out of the Radio Teleswitch Service (RTS). This guide will walk you through what white meter heating is, the implications of the RTS switch-off, and how modern smart meters and flexible tariffs can empower you to manage your home's energy more effectively.

If you are navigating the changes with white meter heating, Fuse Energy offers modern dual-rate tariffs compatible with smart meters, designed to give you greater control and potential for cost optimisation. You can explore our tariffs and switch to Fuse Energy by clicking here.

What is white meter heating?

White meter heating refers to an older electricity metering system primarily designed to take advantage of cheaper off-peak electricity rates, especially for heating purposes. These systems are commonly found in properties, particularly older ones, that rely on electric storage heaters or immersion heaters as their main source of warmth. White meters became popular in the mid-20th century as a way to balance the electricity grid by encouraging energy consumption during periods of lower demand, typically overnight.

How do white meters work?

A white meter system uses a special meter that records electricity consumption at different rates depending on the time of day. It typically has two registers: one for peak-rate electricity and another for off-peak electricity. The meter is controlled by an RTS signal, which automatically switches between these rates. This signal tells your meter when the cheaper off-peak period begins and ends, allowing storage heaters to charge up during the night at a lower cost.

White meter vs Economy 7

While both white meter and Economy 7 tariffs offer cheaper off-peak electricity, they operate differently. Economy 7 provides a single off-peak period, usually seven hours long, typically overnight. During this time, all electricity used in the home is charged at the cheaper rate. White meter tariffs, on the other hand, can offer more flexible off-peak periods than older systems. The key difference lies in the control mechanism: white meters are traditionally controlled by the RTS signal, whereas Economy 7 meters are often time-switch controlled.

The radio Teleswitch service (RTS) switch-off

RTS has been a cornerstone of off-peak electricity tariffs for decades, but its technology is now outdated.

Why is RTS being switched off?

The RTS relies on a longwave radio signal, a technology that is becoming obsolete and increasingly difficult to maintain. The system is analogue and lacks the flexibility and data capabilities of modern smart metering infrastructure. Phasing out RTS is part of a broader industry effort to modernise the energy grid and move all households onto smart meters, which offer more accurate billing and greater control over energy usage.

When is the RTS switch-off happening?

The phase-out of RTS across Great Britain began on 30 June 2025. This marks the start of a transition period during which all remaining RTS meters will need to be replaced with modern alternatives, primarily smart meters.

What happens if you have an RTS meter?

If your property has an RTS meter, it will eventually stop receiving the signal that controls your off-peak heating. This means your storage heaters may no longer switch on automatically or charge at the cheaper rate, potentially leading to higher energy bills if not addressed. Your current energy supplier is responsible for replacing your RTS meter with a smart meter, free of charge, as part of an industry-wide mandate.

Your smart meter upgrade

The transition from an RTS meter to a smart meter is a crucial step in modernising your home's energy management. For more details on the process, you can read about smart meter installation.

Who replaces your RTS meter?

Your current energy supplier is responsible for replacing your RTS meter with a smart meter. This upgrade is provided completely free of charge to you as the homeowner. It's part of a nationwide programme to update Britain's energy infrastructure. You should contact your supplier to arrange this replacement.

The benefits of a smart meter

Upgrading to a smart meter offers several advantages. Firstly, it eliminates the need for manual meter readings, as your usage data is sent automatically to your supplier. Secondly, smart meters provide real-time information about your energy consumption, often accessible via an in-home display or an app, allowing you to monitor and adjust your usage. Finally, and most importantly for former RTS users, smart meters enable access to modern dual-rate tariffs, offering greater flexibility and control over your energy consumption than legacy systems. Dual-rate tariffs require either a smart meter or a multi-register (dual-rate) dumb meter.

Modern tariffs and energy management

Once you have a smart meter installed, you can unlock a new world of energy management possibilities.

How dual-rate tariffs work with smart meters

Modern dual-rate tariffs, often called 'time-of-use' tariffs, work seamlessly with smart meters. Unlike older white meter or Economy 7 systems, these tariffs can offer more flexible off-peak periods than older systems. This allows you to schedule energy-intensive activities, like charging an electric vehicle or running appliances, during the cheapest times, giving you more control over your energy costs. Your smart meter accurately records your consumption during each tariff period, ensuring you're billed correctly for your usage.

Making the most of off-peak electricity

With a smart meter and a flexible dual-rate tariff, you can significantly optimise your energy consumption. Consider programming your storage heaters to charge during the cheapest off-peak windows. If you have an electric vehicle, schedule its charging for these times. Even running washing machines or dishwashers overnight can lead to savings. The average UK home uses around 2,500 kWh of electricity per year, according to Ofgem1, and understanding when you use your energy can help you manage that consumption more efficiently.

Benefits and drawbacks of white meter heating

Understanding the historical context and limitations of white meter heating can help you appreciate the advantages of modern alternatives.

Advantages of legacy systems

In their time, white meter systems offered a significant advantage by providing access to cheaper off-peak electricity, primarily for heating. This allowed households to store heat overnight when electricity demand was low and release it during the day, providing warmth at a reduced cost compared to using peak-rate electricity for direct heating. For many years, this was an effective way to manage heating costs in electrically heated homes.

Disadvantages and the need for change

The main disadvantage of white meter heating now is its reliance on the outdated RTS, which is being switched off. This makes the system unsustainable in the long term. Furthermore, white meters offer limited flexibility compared to smart meters and modern tariffs. They typically provide fixed off-peak windows, which may not align with current energy usage patterns or the dynamic pricing offered by new tariffs. The lack of detailed consumption data also makes it harder for homeowners to understand and optimise their energy use.

Frequently asked questions about white meters

How do I know if I have a white meter?

You can usually identify a white meter by its appearance. It often looks different from a standard single-rate meter, sometimes larger, and may have multiple display registers or a label indicating "White Meter" or "RTS". The easiest way to confirm is to check your electricity bill, which should specify your tariff type, or contact your energy supplier directly.

Is electricity cheaper at night with a smart meter?

Yes, electricity can be cheaper at night with a smart meter, provided you are on a dual-rate or time-of-use tariff. Smart meters enable these tariffs by accurately recording your consumption during different periods, allowing suppliers to offer lower rates during off-peak hours, typically overnight. This gives you the opportunity to save money by shifting your energy usage to these cheaper times.

Can I switch energy suppliers with a white meter?

You can initiate a switch to a new energy supplier with a white meter, but the switch cannot be completed while you still have an RTS meter. As RTS meters are being phased out, your current supplier is obligated to replace it with a smart meter first. Once your RTS meter has been upgraded to a smart meter, you will then be able to switch to any supplier that supports smart meters and offers tariffs that suit your needs.

Making the most of your energy, especially with a smart meter, means having clear information and support. Fuse Energy provides straightforward pricing and in-app usage data, helping you understand your consumption and optimise your bills. Our 24/7 human support team is always available to assist you. Click here to switch to Fuse Energy today and experience a modern approach to energy. You can also learn more about our mission to make energy fair and transparent by clicking here.

References

1. Ofgem. Review of Typical Domestic Consumption Values