On 4 Mar 2004 05:36:23 -0800, in uk.d-i-y
(Lynsey Stewart) strung together this:

Hi, I have a problem with the cold water going to my bath and shower,
and before we go to the expense of calling in a plumber im wondering
if there is something we can do ourselves. The bath is in the far
side of the house, the boiler is in the kitchen, which is in the
middle of the house. The pipes which run into the house for the cold
water is coming into the house from the same side as the bathroom!
The problem is that the cold water tap in the bath is not working.
The cold water is going to the toilet, the bathroom sink and to the
kitchen sink. Why not the bath, when it comes first? We live first
floor flat of an old house.

It sounds as if there is a problem with the header tank, (assuming you
have one), in the loft. More than likely a blockage in the outlet or a
faulty inlet valve.
Or it could be a valve somewhere that has become blocked.
If you have a cylinder cupboard start looking in there for valves with
round red handles, these are, apparently, the work of satan! They
quite easily become blocked with crud from a tank with no lid in the
loft.
--

SJW
A.C.S. Ltd.