Business operators have a responsibility to ensure that all equipment is maintained and inspected by a competent engineer who is registered with the Gas Safe Register.
Regulation 35 of Gas Safety (Installation and Use) Regulations 1998 (GSIUR), requires employers to ensure that gas appliances, flues, pipe work and safety devices are maintained in a safe condition. They should be inspected by a competent person in accordance with current industry practice. Periods between inspections may vary depending on the equipment and its use. All equipment should follow manufacturer's recommendations. As a general rule, annual inspections will be a reasonable minimum frequency.
Restaurant operators should ensure that maintenance works and inspections are carried out by a Registered Gas Safety Engineer who is qualified and authorised to work on catering equipment. They should obtain a satisfactory certificate and keep it on file for inspection by an environmental health officer.
More detailed information can be found from the Health and Safety Executive website.