Hi all... Relative newcomer to trade and doing this between other (unrelated) employments so forgive me if following questions identify me as a little "green". A customer has asked me to look at their boiler/central heating in my capacity as a GSR engineer. The customer had a visit from Gas Safe earlier this year following a gas leak from their gas fire which had been "decomissioned" by a 'qualified' relative who turned out not to be. I can handle the gas issues without difficulty but the GS inspector's report also highlighted some building regs contraventions which were not directly within the Gas Safe remit. These include no boiler interlock, benchmark only part completed and install not notified to local building control. So... my questions: As the installation has not been notified to buliding control, but I believe it pre-dates recent changes to building regs, must I make it compliant to present standards before I can notify it? For new appliances I usually do this via the Gas Safe website (for £2.00 -odd or whatever it is presently). If yes... If I follow the full comissioning procedure in the boiler manual, even though it is no longer brand new, does it still qualify as comissioning and can the benchmark cert be completed to achieve compliance with current regs? Finally... The report highlights the absence of a boiler interlock in the system and the inspector suggests that converting the radiator in the same room as the thermostat from having a TRV to an ordinary lockshield valve would satisy the requirement. Is this correct? As explained elsewhere my primary experience thus far has been on gas elements of installations so, again apologies for any apparently daft questions. I remember receiving a very helpful email with links to a guide to complying with updated building regs on interlocks etc, but, frustratingly, can't seem to find it now it would be useful... Even links to any general data would be well received. Thanks for reading!