An Auckland man's been fined more than $5000 for illegally carrying out gasfitting work.

Chen Hui Ye, who's known as Kevin, has been sentenced in the Waitakere District Court today as he wasn't authorised by the Plumbers, Gasfitters and Drainlayers Board to carry out work at a home in Mt Wellington.

The gasfitting work involved connecting a gas cooker to the gas supply, and connection of a gas water heater to the gas supply.

The gasfitting work carried out by Mr Ye was defective.

Board chief executive Max Pedersen says there are serious health and safety risks associated with work carried out by an unauthorised person - as any defective work can lead to carbon monoxide poisoning and explosions.