In message , Chris J Dixon
writes
wrote:

So far, in this house I've found:
[]
a concealed shower mixer fitted
without thought of how to service it (there's a leak!),

Seriously curious, how would that be done?

Something similar here. Aqualisa shower mixer with the supply and outlet
connections behind tiled plasterboard. Pumped supply and only leaked
when daughters showered.....
Luckily the stud wall was accessible through a cupboard in the next
room. It turned out the plumber had taken literally the instruction to
*hand tighten only* the rubber washer sealed connections.

There was I blaming them for shaving their legs when the problem
occurred because they ran the shower at a higher outlet pressu-)

--
Tim Lamb