I am slightly confused about the flue gas analysing procedures i.e i have to take out an 11yr old worcester floor standing boiler and blank the gas. when all other building work is finished i then have to put it back in the same position and issue a safety certificate. regardless of whether i am servicing, installing a new boiler, or moving old boiler do i have to fill in the flue gas readings on the safety certificate and do i need my energy efficiency ticket. hope you can help a new gas installer.