Cold water tap not working

[Booldawg]

The cold water tap in my bathroom sink has gone from a poor flow to a trickle to nothing over the last month. Its fed from the cold water tank in the loft along with the toilet cistern and bath cold water (which are both fine)

We live in a very hard water area so was wondering if it was a limescale build up? I guess this would also effect the cistern and bath tap? Could it be a problem with the tap or washer itself?

[The Builder]

sounds like a tap problem Booldy....................shut the gate valve that feeds the tap from the tank above............remove the handwheel, undo the shroud and take out the tap valve........see if you can see a problem :o)