I do know one but havent got his details to hand - will find them out and post them on here as soon as I can.

Hi Richard
contact Michael Blackburn at Limonar Construction he advertises on the quesada life website and has done excellent work for us. He can sort out your boiler and his prices are reasonable
Micheal is an Englishman so no language barrier to struggle with. As a matter of interest his wife is spanish so he is fluent in the language. Thats how we feel we get a good deal from him as he knows all the best spanish suppliers locally, so we get the best prices .

Do you know if he is a qualified gas installer? His advert seems to indicate that he is a builder and I do need gas certification.

Richard Im sure he is but do ring or email him hes a straight up guy very easy to talk to and the main part of his ad is as builder but he is qualfied/specialises in many areas. If hes not the guy youre looking for he will tell you however he is great profesional contact on so many levels so it wont be a wasted call whatever the outcome. best of luck