The endorsement scheme, which has been testing and recognising reputable traders for over 60 years, has altered the way it vets contractors and is using REFCOM certification to ensure quality and compliance.

The move came after REFCOM F-Gas and Elite member company Airconco (UK) Ltd, based in London, spent months lobbying Which? to change the way it assesses the competence of listed RAC businesses.

“We have been frustrated for a long time that some companies were promoting their ‘air conditioning services’ on the Which? website, but were not qualified or had been de-registered by REFCOM,” said managing director Gary Woodward.

“After attending one of REFCOM’s Myth & Realities seminars, I was given the facts I needed to feel confident about addressing this issue with Which? Trusted Trader,” he added. “That has led to this fantastic result, not just for my business, but for the whole industry.”

Head of REFCOM Graeme Fox added: “This is a big win against the cowboys, who are operating in the market and placing unfair pressure on good companies who do the right thing. Thanks to proactive REFCOM members like Gary Woodward, Which? will no longer allow sub-contracting businesses to advertise that they carry out air conditioning work if they are not properly registered and licenced to do so.

“Rogue operatives put the quality of services and products at risk, endanger lives and property, and undermine the UK’s commitment to reduce greenhouse gas emissions,” said Mr Fox.