Almost 1m UK households are hooked up to heat networks. None had protection from poor service or price hikes … until last month

‘If I could move, I would – to a place without a heat network. But I can’t while this debt is hanging over me,” says Anja Georgiou.

The mother lives with her family in a rented flat in the River Gardens development in Greenwich in south-east London where, three years ago, residents were shocked to be presented with a surprise £200,000 bill for heating and hot water.

With views of the Thames, and historic Greenwich Park nearby, it is a “very nice” place to live, says Georgiou. The development has a gym and swimming pool and, like many new-builds in the capital, the residents are hooked up to a communal boiler – one of the most common forms of heat network.

Also known as district heating systems, these have been installed in many developments and supply heat from a central source via a network of pipes carrying hot water. The supplier is usually the landlord or freeholder, which buys energy on the commercial market for residents.