Peter Ingram from Lowsonford was fined a total of £2,000 and told to pay £1,777 costs by Stratford-upon-Avon Magistrates Court after pleading guilty to breaching two regulations of the Gas Safety (Installations and Use) Regulations 1998.
The prosecution followed a Health and Safety Executive investigation launched in July 2006 which looked into the removal of part of a flue on a rented house owned by Mr Ingram’s wife.
The tenant had called out an engineer when a Carbon Monoxide detector activated and their 18-month-old son displayed symptoms of sickness.
The engineer disconnected the gas supply and served a Warning Notice marked 'immediately dangerous'.
They noted the flue of the central heating boiler on which Mr Ingram had been working was incorrectly fitted and highly likely to cause the generation of toxic Carbon Monoxide gas within the property.
Speaking after the case, HSE prosecuting inspector Neil Craig said: 'The dangers of incorrectly fitted gas installations are well known. Such dangerous work, like that seen at the property in Stratford, puts lives at risk from both carbon monoxide poisoning and fires in the home.
'This case should serve as a reminder to home owners and tenants that any work undertaken on a gas-fired appliance should only be carried out by a suitable and qualified specialist in that field.
'This instance should also be a warning to landlords that they must provide tenants with a current Gas Safety Certificate and work should only be conducted by persons who are qualified, competent and Corgi-registered.'
The HSE investigation discovered Mr Ingram knew that work on gas appliances was to be conducted only by suitably qualified Corgi-registered installers but even when challenged by a neighbour had continued to undertake the work.
Inspectors found a flue terminal was absent, the height of the flue was insufficient over a conservatory roof and the installation was left with other potentially dangerous faults.
The HSE is advising tenants and home-owners to have any gas-fired appliance carefully checked and serviced by qualified and competent person if they have doubts about its operational safety.
In 2005/6 16 people died from carbon monoxide poisoning caused by appliances and flues that had not been properly installed or maintained. Tenants should also ensure that they are provided with current Gas Safety Certificates.