How to replace a tap washer
Turn off the water supply to the tap and open the tap this will drain the excess water from the tap. Always put the plug in the waste. This will stop any vital parts going down the drain!
You will have to remove the handle of the tap you might need a very small screwdriver to remove the grub screw.
Sometimes this is under a small red or blue bit of plastic in the top. Once the handle has been removed you will need some grips to remove the cover. If you wrap electrical tape around this it will reduce the chances of it being scratched. When you are doing this don’t let the tap move you may have to hold it in position.
Now you should have a hexagonal nut twist this with a spanner once again being very careful not to move the base of the tap. Pull out the hexagonal nut and at the bottom is your washer. Replace the washer with a new one.
If you have brought the wrong washer, don’t panic you can often turn the washer over.This will not last as long as a new one but will stop the dripping for the time being.
If you get a plumber to do this make sure he leaves the old washer so you know he has not just done this. Also make sure the seating for the washer is clean and has no debris lying on it.