There seems to be a glut of posts, mine included, inferring that 'most' plumbers are chancers looking for easy money. My experiences. I have had to contact 14 plumbers to get 4 quotes, of those 14, only 5 replied, 1 of which was polite enough to say that he couldn't do the work as he was fully booked up unitl late August. The rest, didn't bother getting back to me, despite me leaving messages on their answer phones asking for a quote for a supply and fit of new combi.
As for the 4 that quoted, well one was British Gas (enough said), but they were polite. The second was a large local firm, trading on length of service, they matched BG's price, however it took 2 of their engineers to work out a quote, it seemed as if they were trying to confuse me, almost like 'good cop, bad cop' or should that be good plumber, bad plumber.
The third quote, was reasonable, about 2 thirds the price of BG. He listened to what I wanted, didn't try to to manipulate boiler choice, etc, and was prepared to let me do some of the work, basically he was polite, and he also knew what he was talking about.
The last quote was from 'dodgy geezer', cash in hand, and unless I went for his choice of boiler he couldn't gurantee it would work porperly( his actual words).
All plumbers contacted were from the yellow pages in the Corgi section.
You can draw your own conclusions.
Jon