On Fri, 31 Aug 2012 14:48:17 +0100, Tim+ wrote:

What I want to know is, where the feck is all this crud hiding?? This
always happens if I depressurise and repressurise the tank. It's had a
new pressure vessel about 3 weeks ago after the diaphragm failed in the
old one so I know it's not the pressure vessel that's full of crud.

How about the pipe joining the pressure vessel to the rest of the system?

--
Cheers
Dave.