Most modern mixer taps have ceramic washers, rather than the older rubber type.If your tap is dripping, one or both have probably worn out. You'll need to identify the make of the tap, and then there are a number of website suppliers from whom you can see pictures to better identify the exact model. Probably best to order and replace both of them. There is usually a screw hidden under the end of the tap knobs, removing which will expose the washer unit. Having turned off the water (!) you can then unscrew and replace the ceramic units. (I have been here and successfully done that with my Franke tap).
Tim Morris, August 2008
