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Discuss Shower thermostatic mixer tap issues in the Commercial Plumbing Forum area at

  1. Kevin Mooney

    Kevin Mooney New Member

    Good morning everyone :)

    I’m having issues with my thermostatic mixer on my shower, I want to strip it down and clean it up inside but I can’t seem to get in to it, I’m guessing the ceramic cover should come off to reveal a screw but it won’t budge, and doesn’t screw either, I’ve unscrewed the ceramic lever and there looks to be a whole in there that maybe contained a grub screw but doesn’t now, how would you recommend I proceed? Maybe use a bit more force on the ceramic cap? I’m trying with a Stanley knife.



  2. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Yes I would think it should come off , try warm it with a hair dryer or be careful and use a hot air gun
  3. Kevin Mooney

    Kevin Mooney New Member

    Thanks very much, I’ll give this a go :)
  4. townfanjon

    townfanjon Trusted Plumber GSR Top Contributor!!

    Kettle full of hot water maybe
  5. Ben-gee

    Ben-gee Plumber Top Contributor!!

    Maybe on of the four “prongs” unscrews and is hiding a grub screw?
    Worth checking, some do it like that.
  6. Kevin Mooney

    Kevin Mooney New Member

    Do you mean the 4 prongs on the tap with ceramic disc? They don’t come off, but thank you
  7. Kevin Mooney

    Kevin Mooney New Member

    Thanks :) will try that too
  8. steadyon

    steadyon Active Member

    It looks like a shower I worked on recently. If so:

    1. The ceramic index is glued to a threaded brass slug which screws into the cross head of the tap. Scale remover and some very hot water got it free.
    2. The shroud behind the cross head (the smaller diameter chromed bit) has an allen grub screw underneath. Slacken this off and the shroud comes off.
    3. Removing the shroud reveals the valve internals. The internals are threaded into the body of the valve and require a 17 mm Allen bit to remove, together with a lot of force.
    4. Removing the internals shows a chromed shuttle valve which appears to regulate the hot water flow. This sticks quite easily.
    5. The thermostat is a small capsule. You used to be able to get them from showerdoc (Mira "Element Realm" is the cartridge but not the shower) but they appear to be discontinued. They were about £50

    In the end I found it impossible to get parts for this shower (including the numerous O rings) and it has been replaced. I wouldn't spend much time on it unless you know the make and model and find spares are obtainable.
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