Cleaning limescale from inside a bath mixer tap

[trentsc]

A friend's bath has a mixer tap with a circular sliding collar which, when one slides it downwards, activates the shower head. Unfortunately, the slider has stopped working.

We're in a hard water area, so I think the problem might be that limescale has bunged up the mechanism. My challenge, however, is how to remove the limescale from the internal workings without removing the whole tap from the bath (the bolts are all rusted to hell and taking them off would probably mean replacing the taps and mountings).

Any ideas on an effective, simple way of achieving this?

Many thanks.

[stoneyboy]

trentsc,
Try pouring distilled vinegar around the sliding collar and leave overnight. If this doesn't work the collar and mechanism can normally be removed from the tap with taking the tap off the bath. This you can then clean with acid or kilroc.
end

[xo8o8ox]

I had the same trouble but managed to pass a small alan key through the rod that stops the slider springing upwards. I then stretched a balloon over the fitting and cut off the end. Filled with malt vinegar overnight.
Worked the scale loose the next day with movement and washed off. (don't flush out through shower head - it will clog it up!)

p.s. NEVER buy taps (or light fittings) from B&Q. Nothing but trouble.