Hi guys, I have a mixer tap in the bath which incorporates the shower as well (theres an up and down pull tab to switch between the two. Recently the cold tap stopped working, It didnt turn as far as it should and no cold water came out of either the shower or bath. It is a one spout two tap system, If I give it a bang or twist the push pull tab to operate the bath or shower it eventually starts working, Bit confused, Is it a washer inside that needs changing and has got stuck or something? Dont want to buy a new mixer as this one is only a year old!!