No water flow from one tap!

[Andy Man]

I live on the 3rd floor of a small block of flats built in 2000. I was away for a few weeks and on my return found only a trickle of water came from the cold tap in the bathroom basin, whilst the kitchen cold tap water flow was fine. Then, the bathroom basin trickle faded to nothing! I hadn't turned the water off while away and can’t see any leaks. In the bathroom, there is a pressure pump which is switched on when using the shower. Usually, when I 1st switch this on, no water comes from the bath tap or shower head until I run the cold water tap for a few seconds then turn it off!

Luckily for me now, if I leave the bath tap on for a while it comes on, and if I hold the shower head really low, the water flows o.k..

I may have 2 problems here but my main concern is why am I getting no water at all from the bathroom basin tap?

 

[WHPES]

Could be washer jammed onto the tap seat

 

[msw109]

yeah sounds like prob with stop tap