Sounds like the the tap plunger, the bit with the washer on it has stuck fast onto the tap body seating so when tap is turned on the head goes up but the water pressure can't free the plunger. This could mean a new tap. But you could try removing the tap centre first. based on the tap is a mixer with one spout. Tools: an adjustable wrench*** and screw driver,usually crosshead, a small electrical screw driver.
Find your mains incoming tap and turn that off. to release pressure in the pipes flush the loo or turn on the bathroom cold tap and the pressure will release into the loft tank.
Cover the sink drain so you don't lose the tap head screw if you drop it. Use the elec screwdriver to prise off the colour code disc on top of the tap assuming it's that type. undo the screw in the head oh!! did you drop it? now you know why I said cover the sink drain, and remove the head, you may have to work it loose. Place the wrench on the large nut on the brass tap centre piece and turn it anti clockwise, you may need some force. Remove the tap centre the plunger with the washer on will probably be left behind in the tap. Use a screwdriver to work it loose and remove it.
Now If the tap is VERY old replace it, if not then go to the local D.I.Y store with the tap center piece and ask for the matching replacement [ Kitchen taps and basin taps are usually 15mm , 1/2" bath taps being the larger 22mm, 3/4" ]and a tap seat cutting tool, asking their advice on how to use it. ***However if the taps are separate taps then Two adjustable wrenches will be needed, one to hold the body of the tap in a clockwise direction while turning the other one in an anti clockwise direction, If you don't do this then the tap body will turn and cause a leak in pipe joint where it joins the tap.
bob, August 2005
