In article ,
David WE Roberts writes:
....in the water, that is.

Two problems:

(1) When I run the cold mains at full blast (e.g. the bath tap) I get a
few black flecks in the water. Not a massive amount, but I didn't think I
should get any.

(2) When I take the head off the electric shower and run it full blast on
cold, a large amount of cr*p comes out. This seems to be mainly limescale,
black on one side, but there are also some coppery blue bits. I expect the
very old Triton T80 shower to have some clag in as this is a very hard
water area, but it just seems to keep on coming. I thought the shower has
a fairly small area of heating coil and there seems to be an awful lot of
stuff coming out.

I got the same two-coloured pieces in the hot supply from an old
Main multipoint water heater. It was replaced about 5 years ago
with the then current model which has an internal teflon coating
on the heat exchanger pipework, and that seems to prevent scale
building up in the heat exchanger, as it hasn't happened since,
and it's never needed descaling.

We should be getting rid of the shower soon - new heating system which
will run a mains pressure shower - so I'm not too worried about that. I'm
more concerned about the black bits in the cold mains.

If this is from internal pipework this isn't too bad as this is also going
- ripping it all out back to the stopcock (and changing the stopcock
because it doesn't stop).

If it coming in from the mains water supply I would prefer that it did not.

It's probably coming from iron pipework. Do you have iron pipes
either before or after the main stop cock?

--
Andrew Gabriel