I rented a new house and the master shower has a problem. When I turn the knob in the middle to make the water go to the showerhead instead of the bathtub, I turn it all the way but only about 50% of the water goes up top. The other 50% continues to fill the bathtub. I have to assume the valve is bad and needs to be replaced. Is this easy to replace (turn off the water, unscew, screw on new one) or what? I have replaced the washing machine water connnectors before and it was simple, but it was obvious that that was all you had to do. /forums/images/graemlins/1zhelp.gif p.s. I noticed that the tile surrouding the knobs in the shower are a little different, so I assume the tiles have to be removed to do this job...? Any of you guys done this before? I really only want to replace the one knob, but if the whoel thing has to be opened up I might as well replace all three.