Servicing a thermostatic shower valve


5 Aug 2008
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United Kingdom
Hi, can anyone help with disassembling this thermostatic shower valve. I can't see anywhere to unscrew it.

There is a circlip just under the splined part where the tap head attaches (to the right of the picture). Removing that allows me to push the inside of the valve down slightly but not to remove it. Do I need to drift it out a bit more forcefully? I was expecting to be able to unscrew it.

The valve is stiff and has started to clunk when being turned on (a noise like water hammer). I would rather fix it before it breaks!


bsr View media item 86846
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To be honest I usually just replace them. It's not like servicing a tap where you might reseat it, change the washer, repack the gland, clean and grease it. I'm not even sure what to do to service a thermostatic cartridge apart from clean the scale off it externally.
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Update - identified it as a Sirrus Amethyst, cartridge is an SKAK4000.

Unfortunately the part is discontinued. However, it must be possible to disassemble and service because they sell a servicing kit!

A bit of digging and it looks very similar to a Gummers 1500 except the threading on the top of the cartridge (which isn't used in my mixer). I'm tempted to try replacing with a Gummers 1500 cartridge. Any thoughts? I've found the Gummers 1500 servicing video on Youtube and will try that.

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