Almost 1 million homes must replace their Radio Teleswitch energy meters in the next nine months or face loss of hot water

More than 800,000 households with Radio Teleswitch (RTS) energy meters should have their devices replaced by June 30, 2025 to avoid losing access to heating and hot water.

This is under a tough new regime backed by regulator Ofgem. This will see energy companies replace meters in just eight months instead of the original four-year schedule, which would have meant hundreds of thousands of people could have suffered power outages.

RTS meters take advantage of BBC Radio 4’s longwave channel to communicate with energy companies, and many date back to the 1980s.

Energy companies use RTS to switch a meter between peak and off-peak rates, so customers can have energy deals that charge them less at certain times, usually during the night.

There are more than 800,000 active RTS meters in the UK, according to figures from energy regulator Ofgem.

The problem is that the BBC has wanted to close BBC 4 longwave for years and has only kept it running to use RTS meters.

The energy companies pay the BBC to keep these RTS meters running, but the national broadcaster has finally had enough and will shut down longwave Radio 4 for good next June.

The BBC has good reasons for wanting this. Radio 4’s long wave feed depends on a pair of 20-year-old valves with no spare parts left anywhere in the world, so the service is already vulnerable.

Energy companies have been moving customers from RTS meters to modern replacements, usually smart meters.

But the pace of this replacement has been slow, and at the current pace it will take until 2028 for energy companies to fully replace all RTS meters.

But Ofgem has called a summit of major energy companies, as well as trade body Energy UK and the charity Citizens Advice.

Ofgem said: “The RTS system, which uses longwave radio signals to tell some electricity meters to switch between peak and off-peak times, is no longer viable and, without a meter upgrade, some homes, schools and affected businesses could be left without heat. and hot water, or they can’t turn off the heating.’

The outcome of the summit was an agreement to accelerate the pace of replacement of RTS meters.

Ofgem’s Charlotte Friel said: ‘The importance of protecting RTS customers from losing control of their heating and hot water is equally matched by the magnitude of the challenge ahead.

“At the current monthly replacement rate, not all RTS meters across the UK will be upgraded until 2028, so it is clear that swift and drastic action is needed, and I am pleased that suppliers and other stakeholders are responding to our call for bold actions and decisive action.”

Energy companies will focus on hotspots where there are many RTS meters, such as Scotland, the north of England, the Midlands, north Wales and London.