British Gas smart meter warning: Hundreds of thousands at risk of losing hot water or heating as meters to stop working - when will old technology be switched off?

Energy companies have said it will be "very, very difficult" to replace all Radio Teleswitching System (RTS) meters with smart meters before the old technology is switched off on 30 June. Campaigners estimate more than 300,000 homes could lose heating - or have it stuck on constantly - in what energy regulator Ofgem has called "an urgent consumer welfare issue".

The Radio Teleswitch Service (RTS) is a technology used by some older types of electricity meters. These meters often switch between peak and off-peak tariff rates or control heating and hot water. Meters that rely on the RTS have been used reliably since the late 1980s. However, the longwave radio technology it uses will be switched off from 30 June 2025. This change may affect your business.

RTS phase-out was originally planned for March 2024, but Ofgem has confirmed that RTS will be switched off from 30 June 2025. After this date, businesses with meters that rely on RTS may find certain functions no longer work, regardless of your energy supplier. In an effort to pre-empt any disruption, we’re upgrading all affected meters and replacing them with a smart meter free of charge.

A lot of meters across the UK need upgrading urgently. Businesses that delay their smart meter install may find themselves in a situation where their energy supplier is unable to offer an appointment before the Radio Teleswitch Service ends. To protect your business from any disruption, British Gas recommends arranging your smart meter upgrade as soon as possible.

Contact your supplier or network operator, if you:

• Have an electricity meter that switches between peak and off-peak tariff rates, such as an Economy 7 or 10 tariff
• Have a meter that automatically turns on your heating or hot water
• If you’re unsure whether you have a Radio Teleswitch Service meter, you can find more information about RTS meters on the Ofgem website.

At the end of March, there were still 430,000 households using RTS meters for their heating and hot water, according to Energy UK, which represents energy companies. It said more than 1,000 RTS meters were now being replaced each day.

But based on the 430,000 figure, this daily rate would need to be more like 5,000 to stand a chance of reaching everyone. Ned Hammond, Energy UK's deputy director for customers, told BBC Radio 4's You and Yours the rate of replacement was rising, but added: "Obviously we'd need to increase from there significantly still to replace all the meters by the end of June." Energy companies are still targeting 30 June "as things stand", Mr Hammond added, and are developing plans for a "managed and very careful phase down of the system", aiming to protect vulnerable customers.

If your energy supplier cannot fit a smart meter in your home, Ofgem says your supplier must install a "suitable meter", external with no disruption to your service. According to Ofgem, you may have an RTS meter if:

• Your home has a separate switch box near your meter with a Radio Teleswitch label on it
• Your home is heated using electricity or storage heaters
• There is no gas supply to your area
• You get cheaper energy at different times of day, for example, on an Economy 7 tariff
• If you haven't been contacted, Ofgem recommends reaching out to your supplier to arrange the replacement
• However, beware if someone contacts you claiming you need to pay to change your meter as it's likely a scam.