"Christian McArdle" wrote in message
t...
and yet I can walk into any plumbing merchants and buy a boiler
and all the parts to connect it up to a gas supply.

Indeed. I've just done this very thing. I'm not fitting it, though! No one
has once asked me if I am qualified to fit any of it.

Christian.

If they were forced to ask, most merchants would lose a good slice of their
business.

--
Adam