Press release

Lawyers flag risk of anti-competitive conduct to block UK heat pump uptake

26 March 2026

Companies in the UK gas industry may have breached competition law by acting together to undermine the uptake of heat pumps in the UK, lawyers at environmental charity ClientEarth are warning.  

In legal letters sent on 23 February 2026 to 10 companies, ClientEarth lawyers point to evidence suggesting that certain companies joined together to influence the development of the UK home heating market, including by potentially misleading consumers into thinking that heat pumps are not a viable option.  

This comes as the UK Government just unveiled its plan to warm the UK’s homes – which expands the Government’s £7,500 grant for heat pumps.  

Heat pumps are much more efficient and can be cheaper to run than gas boilers. Experts consider the use of hydrogen for home heating unfeasible in part due to requiring quadruple the energy to produce the same useful heat as a heat pump. Because heat pumps run on electricity, they have no direct carbon emissions and are better for the environment than other forms of heating, including gas. They also reduce reliance on imported gas and can increase the UK’s energy security.   

But the uptake of heat pumps by households in the UK remains the lowest in Europe. Addressing misinformation about the reliability and cost of heat pumps will be crucial to address this, according to the Climate Change Committee. 

While some of the companies manufacture, sell and/or install heat pumps alongside the significant gas-focused parts of their business, this does not mean that there is not a risk that, if they acted together, their behaviour could have breached competition law. 

Based on the evidence collected in the letters, the lawyers suspect that the gas companies have:  

  • collectively spread misinformation about heat pumps. For example, investigative reporting has found that a UK  gas trade association hired a public relations firm that stated on its website that it sought to “spark outrage” around heat pumps and that mainstream press coverage subsequently referred to the roll-out of heat pumps as a “Soviet-style” policy, with “eye-wateringly high” prices. 

  • aligned around potentially misleading marketing practices portraying hydrogen as the future of green heating. Companies acted together to mount a ‘Hello Hydrogen’ marketing campaign, claiming that hydrogen was going to heat homes, and that it would be “more affordable” than other “expensive options that take up lots of space”. This messaging risked misleading consumers into sticking with gas on the promise of future hydrogen heating, rather than choosing the competing green heat pump product. That is despite the fact that experts have deemed hydrogen “unsuitable” for home heating. 

  • agreed on the prices of future ‘hydrogen-ready’ boilers. The “Big Four” boiler manufacturers (Ideal, Baxi, Worcester Bosch and Vaillant) entered into and publicised an agreement to commit to set the pricing of future ‘hydrogen-ready’ boilers at the same up-front cost as equivalent gas boilers, apparently to shift perceptions about the significance of hydrogen heating in the UK.   

ClientEarth lawyer Catherine Derenne said: “Heat pumps are a genuinely good heating option for consumers. We know they’re better for the planet than gas boilers and can lower households’ energy bills too.”  

“But whether through misinformation, potentially misleading marketing practices or apparent price fixing, the gas industry seems willing to go to great lengths to paint a rosy picture of sticking with their gas products, while casting heat pumps in a negative light. These efforts appear to have been coordinated, which raises a risk of anti-competitive conduct.”  

“It also leaves the UK lagging far behind other countries on heat pumps uptake – and consumers are sadly paying the price. Consumers don’t have access to the right information about home heating because the gas industry has purposefully muddied the waters.” 

ENDS  

Notes to editors

Read ClientEarth’s letters to gas companies. 

ClientEarth gave the recipients of the letters a right to reply. Responses were received from Centrica and Vaillant. 

Centrica rejected the allegations and inferences set out in our letter. Centrica asked that we publish its response, which is available here, and its climate transition plan, which is available here, and direct readers’ attention to these.  Centrica states that it operates one of the UK’s largest heat pump businesses. However, according to its financial reporting, its installations of heat pumps have been a small fraction of its total home heating installations, with boilers accounting for the vast majority. 

Vaillant declined to respond substantively, on the basis that ClientEarth requested any comments within 3 days, but rejected any suggestion that Vaillant has engaged in anti-competitive conduct, and stated that Vaillant is a market-leading heat pump manufacturer in the UK for which heat pumps are a core market segment in which it is heavily investing. 

Heat pumps are approximately 3-4x more energy efficient than gas boilers and running costs can be lower depending on the tariff and changes in prices, and may fall further following policy changes. Heat pumps do not produce harmful carbon emissions and are a key part of the UK government’s plan to decarbonise homes, reduce energy insecurity and reduce energy bills.  

The sale of heat pumps in the UK has been the lowest in Europe. Even in countries with high electricity prices and large gas networks, such as Germany, take-up has been much higher.   

Due to inefficiencies in the production processes, hydrogen requires 4x as much energy as a heat pump to produce the same useful heat. The Climate Change Committee has recognised that using hydrogen for home heating would delay emissions reductions and increase indirect emissions due to required gas imports, and has stated that there is “no role for hydrogen in home heating”. 

 

About ClientEarth

ClientEarth works in over 60 countries across Africa, the Americas, Asia-Pacific and Europe. We shape, implement and enforce the law, to build a future for our planet in which people and nature can thrive. We are tackling climate change, protecting nature and stopping pollution, with partners and citizens around the globe. We hold industry and governments to account and defend everyone’s right to a healthy world.