A gas fitter has received a suspended prison sentence, curfew, and been ordered to carry out 300 hours of community service after a pensioner suffered severe burns in a gas explosion at his home in Manchester.

Gas fitter Christopher Laffin, 22, was sentenced at Manchester Crown Court on 29 November after an investigation found he had damaged live electrical wires while installing a new boiler at the terraced property, which caused a hole to burn through the gas pipe.

As a result, gas leaked into the property, which was then ignited when Peter Smith, 66, turned on the gas hob on his cooker on 27 September 2011, casing the explosion. Mr Smith suffered burns to 58% of his body and was put in an induced coma for three months to stabilise his condition.

The court heard that Mr Laffin, an employee at AWL Plumbing and Heating Ltd, had burnt the cables while using a blow torch to solder together gas pipes that ran alongside them. He wrapped plastic tape around the cables instead of repairing them, despite them being badly charred.

The investigation found electrical arcing from one of the damaged cables had burnt through the tape and gradually burnt an oval hole in one of the gas pipes, just under a centimetre in diameter. This was wide enough to allow gas to build up in Mr Smith’s home, but he did not notice it because he lacks a sense of smell.

His house was severely damaged, with walls and windows blown out and the conservatory completely destroyed.

Christopher Laffin, of Reston in Staveley, Cumbria, received a six month prison sentence, suspended for two years, will be subject to a curfew prohibiting him from leaving his home between 6pm and 6am on Fridays, Saturdays and Sundays for the next six months, and was ordered to carry out 300 hours of unpaid work in the community.

He was also ordered to pay £1,000 in prosecution costs after pleading guilty to a breach of the Health and Safety at Work etc Act 1974.

HSE inspector Stuart Kitchingman said: “Mr Smith suffered horrific injuries in the explosion which will affect him for the rest of his life, but he could easily have been killed.

“Having burnt through the cables while using a blow torch, it would have been obvious to Mr Laffin that the cables were severely damaged. He should have made sure they were properly repaired but instead he just wrapped them in tape. Mr Laffin clearly wasn’t competent to carry out electrical work, and he should have brought in an electrician if he didn’t know what he was doing.

“Working with gas and electricity are classified as specialist trades for a reason, and it’s therefore vital workers stick to their area of expertise so lives aren’t put at risk.”

More information on electrical safety is available on the HSE website.