How do I fix my mixer tap? The hot tap doesn't allow any water through, it turns once then gets stuck, it was letting water through up to a week or so ago. I have tried blocking the end of the tap and turning on the cold to try clear any air in the hot pipes but to no avail. Hot water comes out of the sink but not this bath tap.

Mike Hague, January 2008

it appears that the washer has worn down and therefore the worm screw in the tap is turning too far down causing the body of the internal jumper, the hexagonal piece, to jam on it's mounting. Try renewing the washer and regreasing the worm screw with silicone grease. It will not be airlocked because the other taps would also be locked.

AB, January 2008