Problem with recently installed Mira concealed shower mixer.

[surv1v0r]

I recently had a bathroom refurbished. This included the replacement of a shower cubicle, a Mira concealed shower mixer and a hot & cold water pump. Following this work, there is a fairly dramatic leak into the ceiling void of the room below the bathroom whenever anyone takes a shower.

There is only a leak when the shower is in use. By using a 1.75m long hose and running the shower with the water going into the hand-basin I have eliminated the cause being due to cracks in the shower base or bad sealing around the shower walls. Nor is the leak is coming from the pump or any of the visible pipework.

My only remaining explanation is that there is a leak either from the shower mixer itself or from the associated pipework. The mixer and the pipework is embedded in a wall covered by tiles.

Can anyone suggest what the problem might be and how I go about investigating it further. In particular, can anyone tell me how to go about removing the outlet connector where it comes through the wall - is it an irreversible push-fit or does it screw on? Likewise, how far can I go interms of exposing the actual mixer valve?

Many thanks for any help you can give me.

Incidentally, the plumber / builder who did the work has had a bereavement and is no help at all at the moment, that will be a problem for a later date.

 

[Plumbstar Tom]

Can you post a few pictures and confirm the model of the shower

Good work on eliminating the sealing of the shower tray!

 

[surv1v0r]

Can you post a few pictures and confirm the model of the shower

Good work on eliminating the sealing of the shower tray!

Sorry, should have done this earlier. I don't know the version of the mixer but here are a couple of photos - hope they help. As you will see, I have started to dismantle the mixer but do not want to attempt more without knowing what I am doing.

 

[Radioman]

Providing the installation was done correctly The large diameter shrewd around the valve body should slide forward and off the valve. Some installers stick it to the tile with a bead of silicone. If this is the case you will need to push a very thin blade behind the plate to cut through the sealant.

Once off you should be able to see the inlets and outlet, again providing the instal was done according to MII. There should be 2 inlets and 2 outlets, 1 outlet being blocked off.


The outlet is normally a push fit over 15 mm copper pipe. The outlet has an internal o ring. Not unusual for that ring to get dislodged or split if a pipe slice has not been used on the copper.

If no obvious sign of leaks then your next and only action will be to remove tiles and plaster to inspect the pipe work. I am assuming that it is not a stud wall.

How long ago was the installation? There seems to be a lot of limescale on the chrome? Also is the hose and head original or a replacement? The incorrect sizes can cause backpressure that can blow the seals in the cartridge causing leaks.

 

[surv1v0r]

Thanks for that.

With the aid of a long kitchen knife (my wife was out shopping) I have now managed to release the surround. Unfortunately, the hole in the tile was made very precisely (by me) and there isn't much chance to see behind it so removing one or two tiles is likely to be unavoidable - and foolishly I didn't think to keep spares.

I have a feeling that plastic pipe rather than copper was used although I don't know what was used behind the tile, I had assumed that from the mixer to the outlet would be entirely Mira hardware. Should I be able simply to pull the outlet off whatever it is connected to after undoing the four screws?

As to the limescale, it is a major irritation here! A new kettle will fur up within a week but that too is another story.

The hose I am currently using was a temporary fix to try and eliminate the possibility of leaks from the base or behind the shower walls. I believe that the head and original hose are both part of the Mira kit but you may well have a point there.

 

[Plumbstar Tom]

unlikely to be Mira components for the mixer to outlet, it will be made by the plumber as the length and position is different every time. your fault could be anywhere along there.

I think tiles will need to be removed or access from the room behind has been done before when possible

 

[surv1v0r]

There is a chrome surround which would probably allow a better view if it could be removed. It appears to be loose(ish) but I don't want to force it off. Should it just pull off or would I need to dismantle the cartridge first? (I replaced a cartridge many years ago).



Access from the room behind (airing cupboard) would probably do even more damage than removing the tiles and if I found something wrong I would probably have to remove the tiles anyhow. The wall is made of Celcon blocks.

 

[surv1v0r]

I have just been having a closer look at the shower mixer and on the Internet. I have come to realise that it is almost certainly NOT from Mira, I believe that it is in fact an Aqualisa Aquavalve 609 shower mixer although I don't see why that would explain the problem I have been having?

There is a lot of limescale on the shower head nozzles (which I have just cleaned) but the problem occurred more or less from day one.

 

[Plumbstar Tom]

looking at the instructions the hole in the wall is wrong, it should have been 130mm diameter:

If installing the product built in to a solid wall, chase out a suitable recess
in the wall to receive the valve and pipe work. If installing the valve in a concealed panel mounted situation, in most cases it will be necessary to first install a suitable sound fixing in the cavity area before fixing the valve. A hole of Ø130mm is required to install the valve and gain access to inlet and outlet connectors.

http://www.aqualisa.co.uk/Aqualisa/...avalve-609-Thermo-Web-inst-guide.pdf?ext=.pdf

 

[surv1v0r]

Do you mean the hole behind the tile or the hole in the tile?

Certainly it would be impossible to "gain access to inlet and outlet connectors" through the hole in the tile. The mixer appears to be securely fastened to a cut-out in the Celcon block. I would imagine that the connections would have been tightened up and tested before the tiles were put on the wall.

 

[Plumbstar Tom]

The whole install should have been tested before tiling over. I would expect the hole to be 130mm all the way to the valve so there is access.

Can you turn the shower on as it is and see if you can see any drips?

 

[surv1v0r]

The whole install should have been tested before tiling over. I would expect the hole to be 130mm all the way to the valve so there is access.

Can you turn the shower on as it is and see if you can see any drips?

I will try to have a look. Do you know if the chrome surround can be removed easily? Would I need to dismantle the cartridge first? removing it would probably allow a better view and it does appear to be loose(ish) but I don't want to force it off.

On another front, any tips on removing a tile from a Celcon block wall? I have located two replacement tiles . . . under the bath.

 

[Chalked]

I would take a bet that one of the (old) connections not the shower valve I'll be leaking. On aqualisa mixers they have a rubber ring inside to seal. Even though your plumber maybe hasn't undone them, they will leak is disturbed.
If the hole had been cut 25 mm larger ( still can be) it will allow acces to these connections. Bt beware, on old plastic fittings they can go brittle.
If it's not that, then remove the shower wall outlet and look at that.

Tbh if I were you I would be getting another plumber round. Then pass the invoice on when the dust has settled with the Berievement.

 

[woodsy]

The wall elbows generally are of a pushfit nature with a rubber o ring.I would be taking that off first to check it hasn't been pushed out or that the pipe itself isn't too short because if the pipe can move backwards when the shower is turned on it will pop out.

 

[Chalked]

Here's an exploded view of your mixer.

 

[gassafe]

If seen no 8. Split before with age, big leak through the ceiling when shower operated!

 

[surv1v0r]

Here's an exploded view of your mixer.

Thanks for that exploded view of the mixer. Do you know if the chrome cover (Item 3) should just pull off? I suspect that if I can remove this I would be able to get a better view of the fittings.

Incidentally, the mixer is not an "old" one, it was new when the shower was installed recently.

 

[Best]

Yes, the shroud just pulls off, unless glued with silicone.
That valve does seem to be the old design? It goes back a couple of decades!
I have just replaced a cartridge on identical model.
Be careful there is not a leak at the cartridge spindle when the shower is being used (and for a while afterwards due to water coming back down from shower hose and handset.) I have seen this happening. Only other possibility is the only dormant pipe is the outlet towards the hose, but all behind tiles, which could leak when shower is turned on

 

[Chalked]

Removing no 3 will not help. You need to drill the tiles in a circle 10mm inside the silicone and break it out. This will let you view the connections.
As above. I too have seen no8 just crack without notice.

 

[Radioman]

As all above, I suspect this was not a new valve as the new valve kit comes with a EPP mortar guard that denotes the area to be left around the valve to allow access to the valve and connections. Plus the new valve comes with a 5 year guarantee. Take the outlet off, just remove the 4 screws and pull off. Inspect the o ring for damage or displacement when installed. Easily done if the pipe was not cut with a pipe slice or cut too short, there is a measurement in the installation manual for length above tile surface. If all OK get hold of a 15mm push fit stop end and push onto pipe. Turn on shower, if still leaking then the issue is either the blanking cap no 8, connection or in the supply to,hose pipe work and or connections. In any case you are going to have to either make the valve access hole bigger by chain drilling or removing the tile. If the former be very careful not to drill into a feed pipe. Incidentally if you had called Aqualisa out on a warranty call they would have voided the warranty due to no access to the valve. Section 15


http://www.aqualisa.co.uk/Aqualisa/...avalve-609-Thermo-Web-inst-guide.pdf?ext=.pdf

However the tiles look fairly generic so why not try to get some more?

And while your at it have a look at Kinetico water softeners.

 

[surv1v0r]

I am quite certain that the valve is a new one (or was when it was fitted). It is an Aqualisa Colt Concealed and it cost £237.14.

I have found two spare tiles so I will have a go at removing the tile - any suggestions as to how best I can do this? It is fixed to a Celcon block wall which I would rather not damage too much.

 

[Radioman]

I am quite certain that the valve is a new one (or was when it was fitted). It is an Aqualisa Colt Concealed and it cost £237.14.

I have found two spare tiles so I will have a go at removing the tile - any suggestions as to how best I can do this? It is fixed to a Celcon block wall which I would rather not damage too much.

Best way to remove the tile is to work from the center towards the outside. They look like biscuit glaze to me so should be failry soft. If porcelain proceed with care! Protect the tray with towels or dust sheets or thick cardboard, wear proper gloves and eyeprotection. GENTLY tap the center of the tile with a hammer until it cracks, then using a thin blade prize the shards away.

Depending on the type of cement used you may or may not bring away the plaster, a proper waterproof cement will, but if you used a showerproof then it may not. If you do then you can make good by cleaning down, 2 coats of PVA, a small amount of Hardwall or Bonding to level off then your tile cement, you could use a 1 coat but I wouldnt out of choice.

Remember when you replace the tile that you need to leave the area around the valve clear for maintenance etc. Thats what the mortar guard is for. Also worth noting that the later plastic bodied valves dont like to be in contact with gypsum based products.