A gas engineer from Willenhall, Walsall, has been prosecuted for illegally carrying out work at a house in Cannock, Stafford.
Leslie Morgan issued a gas safety certificate after installing a boiler despite not being a Gas Safe registered engineer.
Stafford Magistrates' Court heard Morgan's original gas safety training and registration permitted him only to work for a previous company and had expired.
The Health & Safety Executive (HSE) wrote to him in 2008, telling him to stop work or become properly trained and registered, after he was found to have carried out unregistered gas work the previous year.
However, Cannock Chase District Council raised concerns about a gas safety certificate issued by Morgan to the Cannock Road landlord and on further investigation the HSE found the certificate was issued illegally.
Morgan pleaded guilty to breaching Regulation 3(3) of the Gas Safety Installation and Use Regulations 1998. He was fined £4,000 and ordered to pay £1,900 costs.