I totaly agree, i'm not anti plumber i'm anti plonker, but the the installations i have described are the norm and as someone who likes a quite life i wish there were better trades men across the board, the op was wondering about why all singing all dancing heating engineer would charge more, and my point as a gas fitter is that i spend alot of time and effort tiding up after cheap chappies who call themselves plumbers, the customers are very happy with the work until someone like me comes along and mentions ventilation, sludge, working pressure, flow rates, etc.. this is not something i would have to do after a competent plumber, as i said there are no regs here so most plumbers don't have the same idea on installations as in the uk where most installations follow some sort of good working practice ie w plan, s plan, flushing, drain offs, filling loops etc....