My Tivoli 11 shower mixer tap ( about 5 years old) has the problem that when turned off and left for a few hours it is then very hard to turn back on again - needing considerable strength by my standard. Any help appreciated I've just refurbished the shower room new cubicle wetwalls etc but decided to keep the original mixer tap. The mixer is a bar with flow regulator tap on the left ( this is the one that sticks) and temperature control tap on the right. [/url]