Such vitriol towards someone who came here for a little (free) help.
Isn't that what this site is about? I don't remember ever getting paid for giving help, nor ever paying for received help.
Perhaps it would be better if the OP started off his post with "I have a friend who...", included the phrase "...he took 280 Euros off him and it's still no better...", and finished with "He can't afford to have someone else over on his disabled ex-serviceman's pension."
OP, this boiler uses (I think) flame rectification to detect the presence of a lit pilot. This relies on a good electrical earth. You might find you have to have a professional electrician in to determine what work is necessary to bring the installation up to national standards. Simply running a long wire from the mains earth terminal to the boiler earth terminal may be dangerous if carried out without regard to other possible hazards.
Yes, there are cowboys in the heating industry, as there are in garages, furniture shops, solicitors' offices, and possibly even banks. The guys on here are giving advice and help for free, and that's not a trait I associate with cowboys. Some seem to spend more time berating the DIYer than helping, but that's just a personality disorder identified recently as Agilitus-selfimportantus. There is a treatment, I'm told, after a fixed diagnostic cost; but I've not gone into it further.
MM