Stop Valves don't seem to work on concealed mixer.

[frusc]

My concealed mixer has developed a drip so I figured it was time to change the cartridge.

I took the controls and panel off and the tiler had only cutout for the 3 controls, so I had to use a holesaw to expose what I presume are the stop valves either side of the mixer control. (I mention this incase anyone presumes they must be the stop valves since they have been cutout by the plumber/tiler).

Unfortunately the stop valves don't seem to have any effect on water flow. I turned them clockwise until tight. I then tried anti clockwise and they start to leak after being turned 45deg from the original position.

Has anyone come across similar looking stop valves? Or am I an idiot and theyre not even stop valves

I thought it best to check, rather then forcing them to turn further (with some sort of lever) and potentially damaging them.

I have another bathroom, but the Mrs is getting twitchy already, so any help/advice greatly appreciated

IMG_1851

• frusc
• 19 Aug 2018

 

[frusc]

Hmmm, having done some further searching I presume these are in fact the filers/check valves

I guess (hope) the stop valves are under the bath as there is a grouted in panel there. But I'd presumed that was for accessing the drain, rather then stop valves, as to me it would have made sense to place them by the mixer :/

 

[just pumps]

Don`t look like any isolating valves I`ve seen. They might be in the loft if the pipes comes down from there.

 

[frusc]

Don`t look like any isolating valves I`ve seen. They might be in the loft if the pipes comes down from there.

Thanks for the response. I'm coming to the conclusion they are in fact filters/non return valves for the mixer

I've cut out some more of the board and can see one of the supply pipes runs down towards the bath. So think (hope) the plumber has put stop valves under there. There is a grouted/screwed in tile panel there. Not easy to remove the grout and dont want to chip a mosaic tile, so either got to grab a grout knife or be lazy and pay for one of those electric removers :/

There is also a supply shut off for the whole house. But I have a megaflow and 3 other bathrooms, so would rather not faff around draining then refilling the entire system.

 

[ReganAndCarter]

I would be more worried that the installer seems to have used ordinary plaster board behind the tiles. Slightest failure of the grout/sealant will see the board disintegrate. I would only use backer board in a shower area.

 

[frusc]

I would be more worried that the installer seems to have used ordinary plaster board behind the tiles. Slightest failure of the grout/sealant will see the board disintegrate. I would only use backer board in a shower area.

Another thing to worry about in that case. Especially considering there are 2 bathrooms and 1 shower room. And its been 8 years, so whilst I have some spare tiles, I probably wont be able to get any more now if the boarding fails and needs replacing.

 

[dilalio]

They are filters and or NRVs.
As you are looking to change the cartridge you must have the make and model of the mixer, which means you would be able to get the MI's no? They would give you the info you need on the valves.

 

[frusc]

Removing the grout on the access panel is a PITA. Has anyone got any experience of using the dremel grout remover attachment, or a dedicated remover?

I could just rake it out, but presume I will need to access the other bathrooms stop valves as well to change the cartridges (havent dripped yet, but they are equally old). Also given ReganAndCarters post, I should probably address any failed grout quickly.

 

[frusc]

Both the Megaflow and shower are on the top floor of the house. Would I be better off shutting the cold supply from the mains, draining until the show stops running?

I'm just concerned about issues refilling the system without air pockets/etc. Never had to drain/refill an unvented hot water tank before.

 

[dilalio]

It's mains pressure, it'll be fine

Just shut off mains and open taps lower down.

 

[frusc]

It's mains pressure, it'll be fine

Just shut off mains and open taps lower down.

Should have asked before I tried chipping away at the grout Given myself a job repairing that now :/

Will shut it off (looks like theres a stop near the boiler/megaflow) tomorrow after kids and Mrs have had there shower/bath. Just in case something goes wrong

And this has reminded me I need to get it serviced as well. Presume asking for recommendations isn't allowed here?

 

[dilalio]

Where in London are you?

 

[frusc]

Near Uxbridge

 

[frusc]

Just to update the thread for anyone else that comes along with the same issues/questions:

1) They were filters and not stop valves. Opened them an cleaned them
2) Shutting off the mains didn't cause any issues as you all advised.
3) Finding a matching cartridge was a PITA. Lots of generic ones that looked similar, but were out by a couple of mm's. Eventually I realised the colour of the cartridge was the key, I searched on that and found a matching one on Amazon

Hope that helps anyone else with the same issue.