On Wed, 25 May 2011 17:41:49 +0100, "Ret."
wrote:

I have completely dissassembled
both cartridges and all four ceramic disks appear perfect to the eye.

#2: Buy replacement inserts (if you can find correct type!).

I think this is what we will have to do - although it is annoying when you
cannot see what is causing the problem!



I wonder if the discs have worn dished or domed. Not that the outcome
is changed much either way.

If you have the disks out you could try lapping them on a flat surface
(Eg. A piece of glass) with jewellers rouge or toothpaste even.

OK. I have B&Q and Plumbworld on the doorstep, and Homebase within 20 minute
drive - so this will be the next step I think.

Derek G