On Sun, 17 Aug 2008 13:50:35 +0100, Bob Minchin
wrote:

Do these taps sometimes drip? My hot water system is low pressure with a
header tank so only about 8' head. Do these taps need higher pressure to
seal reliably?

With a German set we have I've found the ceramic bits last well but
the cartridge assembly has a brass outer casing and that wore down at
the tap end. The result was that the silicon rubber pressure pad
wasn't exerting enough pressure on the ceramic bits and a slight
leakage occurred. The solution was to machine a couple of stainless
steel washers to go at the opposite end to the ceramic discs to get
the spacing right again and reduce wear on the brass.

As you have hard water, when you dismantle the cartridge let the
ceramic bits soak in descaler before reassembly in case a bit of scale
build up has taken place.