I found a huge boiler nerd to service mine. Took him hours, and clearly he loved every minute - he was quite surprised when I didn’t want to stay and watch, and listen to him explain every last bit of what he was doing. There was similar inflation required, although less grot in mine!
He had developed his own detailed checklists that he used for every job, customised to each boiler model. All for £65 as well. He was great, so nice to find someone who really loves his job!
Edit: other people I’ve contacted re servicing have often said that there’s basically fuck all they can check or sort out, they’re best just left until they break, then you fix them if you can. Boiler nerd man is different.