Lara
The tap washer needs replacing or the tap needs degunking when youve got it apart.
Turn off mains water coming in drain down tank in loft by opening bath taps and run untill almost stopped then carefuly remove (lever off)center of tap handle to reveal screw and open screw to remove tap handle
use a spanner to remove the brass body of the tap - i think this is a 15 or 17mm cant remember- then check condition of little rubber washer on bottom of body once its out. there is a clip on the top of the tap under the splined bit this pushes off and the splined bit pushes down through the body and out with a twist. clean grease and reassemble or better still cheat and buy a new tap insert fron the local diy store then build it back up the way you took it apart. turn the water back on at the mains and once there is water coming from the taps in the bathroom again close them amd let the system fill..dont run the immersion during this youll bust it. best of luck I did a longer write up on this for another thread back in November if you can find it but this should see you right and B&Q do a howto sheet on this as well i believe. or ask in store.
