More than 500,000 households on heat networks could face disproportionately high heating costs this winter as their bills are based on un-capped commercial energy prices that have doubled, Heat Trust has warned.

The consumer champion for people living on heat networks has called on the Government to introduce urgent price support to protect customers from unaffordable increases in heating and hot water bills.

In a joint letter to the Chancellor of the Exchequer and the Secretary of State for Energy Security and Net Zero, Heat Trust and the Association for Decentralised Energy (ADE) – the trade association for the heat network sector – warn that heat network households risk being hit much harder by rising energy prices than those with individual gas boilers.

Heat networks supply heating and hot water to multiple homes and buildings from a shared central source. They are expected to play an increasingly important role in Britain’s future energy system, with the Government estimating they could provide almost 20% of UK heat by 2050.

Ofgem took over regulation of heat networks in January 2026, when the Government announced new protections intended to shield customers from unfair price hikes and bring their rights closer into line with households using traditional gas and electricity supplies.

However, heat network customers remain outside the domestic energy price cap or any equivalent price protection.

While Ofgem now sets rules around ‘fair’ pricing, its regulatory framework does not include an equivalent to the price cap for domestic gas and electricity.

Heat Trust says this leaves households without the same protection from sharp movements in energy prices that customers with their own gas boiler enjoy.

Stephen Knight, Chief Executive of Heat Trust, said:

“No household should be expected to cope with their heating and hot water bills doubling overnight, but this is what those on heat networks now face unless the government steps in.

“There is nothing that heat network customers can do to protect themselves from these rising costs. That makes it all the more important that Government steps in to ensure they are not left with unaffordable bills this winter.

“Ultimately Heat network customers need new price protections to shield them from the volatile commercial energy markets, just like other domestic energy consumers get via the price cap. This disparity should not be allowed to persist.”

Heat network operators typically buy the gas or electricity used to generate heat through commercial energy contracts, meaning increases in un-capped non-domestic energy prices can feed through to customers’ bills.

The cost of a typical 12-month commercial gas contract is already around double what it was for the same period last year, with wholesale gas prices potentially rising further as a result of the conflict in the Middle East.

Heat Trust and ADE estimate that, if these increased costs are passed through, heat tariffs currently at around 10-15p/kWh could rise to 20-30p/kWh over the winter – that means households could see their heating and hot water bill rising from around £840 to £1,680 (an increase of more than £800).

Customers on older heat networks, including many on social housing estates where gas use and heat losses can be higher, could be among those most affected.

Heat Trust and ADE are calling on the Government to introduce a price support mechanism to prevent heat network customers facing disproportionately large increases compared with households with individual gas boilers.

They point to the former Energy Bills Discount Scheme, which provided increased support to heat networks with domestic customers during the energy crisis, as an example of how targeted support could work.

Heat Trust and ADE argue that a similar mechanism could limit increases for heat network customers to a level closer to that faced by households protected by the Ofgem price cap.

Keeping heat tariffs to no more than around 15p/kWh would mean an average household would pay a maximum of around £1,200 a year for heating and hot water, before any fixed charges.

ENDS