How can I fix my Whitewater Aspen recessed mixer shower - the control knob keeps turning and won't turn the water off, have turned the water off at the stop taps and removed the outer cover to show the brass controller, can this be replaced?

MARK, October 2008

My shower thermostatic valve is a ShowerStream bought in 1993 from Texas homecare and manufactured by Meynell. I think it is similar to the one cited here.
Thank you John Boy. Having failed to unscrew it with a socket set and a club hammer. I moved on to a impact driver and was then looking for some suitable pipe to use to extend the leverage on the socket set tee bar then I noticed the LH embossed on the nut!
Thank you too, Richard. I didn't use plastic bags but managed to lever in the three clips with a long electrician's screwdrivers. They then held the wax element horizontally so I could reassemble the valve.
Barry

Barry Hursell, November 2021

Remember the brass assembly is a left hand thread, you would be amazed the people that try to turn it the other way and of course with no success.
Its http://www.showerdoc.co.uk/shower-spares/meynell/safemixV6.htm

better to buy the complete repair kit found here:-

John Boy, June 2009

It is a Left Hand thread, so you have to turn clockwise to loosen.

Ambe, June 2009

I had the same problem (BTW is anyone else posting this in a Bryant House built between 97 and 2002?), and here's my fix. The thermostatic capsule (looks like a bullet with a shiny rod sticking out) has to placed 'just so'. The mixers are assembled flat so there's no problem; but once in situ a poor design gives problems. If you shine a torch into the mixer you can see three brass prongs, the blunt end of the capsule must be in between these. Unfortunately the slightest vibration when screwing the cover back causes the capsule to drop down, when screwed together it pushes one of the prongs permanently keeping the water cock open. I used something from my fishing tackle; plastic bags made of a water soluble plastic are packed around the capsule holding it in the correct position while the cover is screwed back. You must thoroughly dry the inside of the mixer first otherwise the bags start to dissolve too soon. When the water is turned on the bags very quickly dissolve and the mixer works fine. FYI fishermen use these bags filled with bait pieces and tied to the line to ensure 'free samples' are going to surround your baited hook when the bag dissolves.

Richard Dawes, February 2009

I also have the same problem. I managed to get the plastic cover off and tried to undo the brass fitting but it wouldn't budge!

I went to Homebase but they don't sell mixers.

Graham, February 2009

I have exactly the same problem. however I cannot remove the plastic cover as there does not appear to be a screw - was this straight foward for you. In answer to your question if you have not yet resolved this - the shower valve should be replaceable, but there may be some damage to your surrounding tiling.

chris o, December 2008