This morning when trying to take a shower, the mixer tap on my bath wouldn't work properly. I have to push a 'collar'-type thing down in order to switch from bath to shower setting. For some reason this morning, the collar refused to push down fully and therefore would not stick on 'shower' position. Any ideas how to fix this kind of problem or am i better off just getting a whole new unit?

Jon Lawson, June 2006

There's probably a limescale build-up under the collar.
Apply a proprietary descaler, then get under the collar with a toothbrush.

Big Softy, June 2006