Difficulty removing flow control handle on Bristan shower

[ED209VSROBO]

Hi,

I am hoping someone can give me some tips / assistance with this issue. I have been attempting to take apart my shower unit to try and replace / service the cartridge inside and i am encountering a few problems taking it apart.

I have managed to get the outer temperature control handle off via its grub screw, but the flow control handle beneath it wont shift despite removing its circlip. I have tried several times using a lemon / white vinegar mix on it to loosen any limescale deposits but its still not shifting. I am pretty confident there is no further grub screws to remove as the manual says it should just pull off once the circlip is removed (See photo) but there is no play in the fitment at all in forward motion. It feels at this point like i have no choice but to resort to blunt force to try and break the seal thats gripping it on, any tips / other things i can try?.

The unit is a Bristan Prism Thermostatic Mixer Valve from 2012, i cant seem to find any further info on it on the internet beyond what i have.

 

[Laurieo]

Have you tried putting back the lever in item 29 and giving it a gentle tap up and down ,may loosen its grip .

 

[ED209VSROBO]

Yes the flow control handle (29) rotates fine clockwise and anticlockwise, it just wont pull forward for removal to see the cartridge behind it. I suspect limescale is holding it in place, as according to the manual there is no further fixing holding it.

 

[conny]

Try a bit of washing up liquid around the back edge, (35), and with the handle back on, wiggle from side to side.
Don't rush it. be patient. A few, very light, taps with a soft faced mallet may help to get some movement.

 

[ED209VSROBO]

Thanks, ill try and give that a go.

Just now prior to reading this i tried using a small flat head screwdriver inserted in the handle hole (29) and giving gentle forward / back movement but still no luck. When the gentle prying movement forward / back is performed some water will leak through the faceplate, so i suspect the flow control handle is vice gripped onto the cartridge.

 

[ED209VSROBO]

Problem resolved .

I managed to eventually remove it by using small flat head screw drivers (then larger ones) to very slowly 360 degree prise round the outside of the flow control handle mm by mm till it came off. Had the same problem removing the cartridge once that was exposed but used the same techniques and it eventually came out. Now all sitting in a white vinegar / lemon bath to hopefully descale.

Hoping once descaled my hot / cold water problem with the shower will be resolved, otherwise i guess ill be buying a new cartridge.

This video on YouTube is useful if anyone else is trying to remove a Bristan Prism Thermostatic Mixer Valve (Not the same as my model but very similar).

www.youtube.com/watch?v=D2tn-QxLL_Y&list=WL&index=2

Thanks for the help.