This does prove that some Gas Safe registered Techs can be ignorant about boilers and how to repair them. And when "professionals" on this forum then claim to know the cause but refuse to provide any assistance it does a lot to further undermine confidence in the abilities of tradespeople in the domestic gas industry.
I have a contract with reputable organisation, who supply apprentice trained Gas Safe registered Techs, with many years of experience, to come do the work
well bernardgreen do you suggest we give gas advice then ? and you seem to put gas engineers down on this forum at every opportunity , seems like sour grapes to me . remember you may need help someday , but if RickH thinks of staying with this company with what he has experienced /witnessed maybe he may consider using someone else .