A sharp increase in prosecutions over illegal gas fitting has prompted warnings against employing unregistered tradespeople.
The Health and Safety Executive (HSE) said 17 individuals have been convicted of carrying out gas work illegally since the start of 2025, compared with three in 2022/23 and four in 2023/24.
Over the past five years, the regulator has successfully investigated and prosecuted dozens of people for breaching gas safety laws by working on appliances without Gas Safe Register accreditation.
Marking the start of annual Gas Safety Week, the HSE warned that improperly installed or serviced boilers, cookers and fires can lead to gas leaks, explosions, fires and carbon monoxide poisoning.
HSE principal inspector of gas safety Steve Critchlow said: "Gas Safety Week is the right time to remind people just how serious the risks of illegal gas work can be, and the rising number of convictions of rogue traders carrying out unregistered gas work should be a warning to everyone.
"Temperatures are going down and bills are going up, but cutting corners when it comes to getting your gas appliances properly serviced by a registered professional could be a fatal mistake.
"Uncontrolled gas leaks can cause fires, explosions, and carbon monoxide poisoning; and even though the gas industry has an excellent safety record, every tragic incident is one too many.
"As people start thinking about their heating ahead of winter, it’s exactly the right time to say, check your engineer is on the Gas Safe Register before you let them anywhere near your gas appliances. If they’re not on the register, don’t let them through the door."
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