Households relying on ageing electricity meters have been told to act now or risk losing heating and hot water.

Energy regulator Ofgem has issued an urgent alert to around 100,000 remaining homes still using Radio Teleswitch Service (RTS) meters, warning that the signal which controls them is being switched off.

In a social media post, the watchdog said: “The signal to Radio Teleswitch (RTS) meters is being switched off.

“All remaining RTS meters will be phased out this year.

“If you have one, contact your energy supplier now to book a replacement and avoid the risk of losing heating and/or hot water.”

What is happening?

The technology that supports RTS electricity meters is being switched off in stages, area by area, from June last year.

Without the signal telling them when to switch between peak and off-peak rates, RTS meters may no longer work properly. That could mean heating and hot water systems failing to operate as normal in affected homes and businesses.

Suppliers should already have contacted customers with RTS meters to arrange an upgrade to a smart meter.

They are required to ensure households have a suitable replacement installed and that services are not disrupted.

Who is most at risk?

You may have an RTS meter if:

• Your home has a separate switch box near your meter labelled “Radio Teleswitch”
• Your home is heated using electricity or storage heaters
• There is no gas supply in your area – common in rural communities and high-rise flats
• You are on a time-of-use tariff such as Economy 7, Economy 10 or Total Heat Total Control.

Homes without gas central heating are particularly affected, as many rely on off-peak electricity to charge storage heaters overnight.

What suppliers must do

As part of the phased switch-off, suppliers must:

• Provide clear, accessible and timely information about the phase-out
• Explain the impact and replacement process
• Maintain high customer service standards
• Offer an enquiry service for households – including vulnerable customers – to report issues such as power cuts at any time of day during the week
• Move customers onto a suitable smart tariff reflecting their usage

Suppliers are also required to treat all households and businesses fairly, including identifying those who need additional support.

Who do you contact?

Households should contact their electricity supplier directly to arrange an upgrade.

Major domestic suppliers include: British Gas; E.ON Next; EDF Energy; Octopus Energy; OVO Energy; Scottish Power; SSE; 

Utilita Energy; Utility Warehouse.

If you do not know who your supplier is, Ofgem says you should follow the steps on its “find your energy supplier” page.

What happens if you refuse a smart meter?

Ofgem says upgrading to a smart meter is the best option for RTS customers.

If you choose not to upgrade:

• Heating and hot water may be left continually on or off
• Storage heaters may charge at the wrong time of day
• Bills could rise if peak and off-peak usage cannot be confirmed
• Tariff choice will be more limited

A smart meter will continue to offer timed switching while also automatically submitting readings, enabling access to smart-only tariffs and accurate bills based on actual usage rather than estimates.

If you need help

Customers in England and Wales can contact Citizens Advice here for free and impartial advice about their energy supply. In Scotland, advice is available through Energy Advice Scotland here.