Concern old meters still in use ahead of switch off

Older meters need to be replaced due to the end of the longwave signal

There are concerns that people still using old RTS meters could be left without electricity or hot water if they do not have them replaced before the summer deadline.

Energy UK estimates that about 260,000 people in the south of England still need to make the change.

Designed in the 1980s, the meters use radio signals to switch between peak and off peak targets, but the technology will become obsolete at the end of June.

Despite a national campaign to raise awareness, energy suppliers are now racing against the clock to achieve the switch off, which they say is a "significant undertaking".

Joe Richardson, operations director for Octopus Energy, said: "We're quite worried for customers who don't replace them, as their heating might get stuck on or might not come on at all and they might not have hot water."

"We really want people to get in touch with us to have these meters changed as soon as possible. It's important not to wait until the deadline."

Ilke Weiss from Goring recently had her old RTS meter changed to a smart meter

Homes using RTS meters are typically in areas with no mains gas supply, and the property is usually heated using electricity or storage heaters.

The meters often have a separate box next to the electricity meter, and are labelled differently, according to Money Saving Expert.

After updating her home heating system, Ilke Weiss from Goring recently had her old RTS meter changed to a smart meter.

Unlike traditional meters, smart meters can record half-hourly price and consumption data and provide automatic meter readings to your energy supplier.

Anindita Sarkar is from the Citizens Advice Bureau in Reading

"The RTS meter was here when we moved in, it was a night storage heating system and therefore we had day and night electricity," Ms Weiss told the BBC.

"It's very good to get rid of this old one, as we also got rid of the night storage heater - every little step towards being more ecological and sustainable is good."

Some charities told the BBC that fears over smart meters could be holding people back from having their old RTS meter changed.

Anindita Sarkar, from the Citizens Advice Bureau in Reading, said people were "worried" about smart meters, despite the fact they work well "most of the time".

"It is technology so might have interruptions but when they're working well smart meters have many advantages," she added.