Bob, Where the property in rented even if commercial then a safety check should be undertaken annually which includes a tightness test downstream of the emergency control valve. Where the commercial premisis is owned and site occupied then it is down to the owner to ensure the gas installation is safe. The only way to acertain this is to ensure that the appliances are serviced and checked for safety by a qualified Gas Safe commercial engineer who should follow manufactures installation and service instructions along with the codes of practice and IGEM standards such as IGE/UP/1A. So therefore annually. Most commercial premisis arrange for this during shutdown periods. Hope this is of help.

Hi Bob It has been some time since I worked as a Gas Engineer, but looking at the Reg 35, it is a general duty to ensure no injury or harm. You would expect the soundness test and service and inspection to be done by a registered engineer. They would recommend annual! I used to carry out tests and inspections for a Local Authority, and this was done annually. Ian

Hi Bob You may well say that, and if you are confident you would be covered in the event of a gas leak, then you may wish to go ahead with a longer time period. I would not recommend that, either in my current role as a safety manager, or in my previous role as a gas engineer. Ian