Exposed valve bar mixer shower????

[smaggs]

Hi, new to this and I'll try to cut a very long story short! After spending =A3280 on a Triton super duper shower, and paying a Corgi registered plumber to fit it (about another =A3100), we're told by Triton and the Water Board that our pressure and flow isn't enough to supply the shower, hence why it keeps failing.

So now we're told that we need a bar mixer to work off our Combi. Here's the difficult bit!

We're re-doing the bathroom next year, so dont want to spend out on an "exposed valve" shower now only to find we cant hide all the pipes next year.

Can anyone offer advice? As the original plumber is telling us he'll need to charge us for his time if he has to go out looking for a suitable shower for us (even though he didn't do the pressure and flow tests as specified in the installation manual).

Anyone give me any advice? Particular showers to go for etc? I'm starting to lose sleep!

[Doctor Drivel]

So now we're told that we need a bar mixer to work off our Combi. Here's the difficult bit!

We're re-doing the bathroom next year, so dont want to spend out on an "exposed valve" shower now only to find we cant hide all the pipes next year.

Can anyone offer advice? As the original plumber is telling us he'll need to charge us for his time if he has to go out looking for a suitable shower for us (even though he didn't do the pressure and flow tests as specified in the installation manual).

Anyone give me any advice? Particular showers to go for etc? I'm starting to lose sleep!

[deckertim]

Doctor Drivel wrote: The

This was certainly a surprise to me. (I hope don't appear too sceptical) Is this a British Standard or an international one?

[Doctor Drivel]

They are near all 150mm centres. If you have 1/2" male BSP tails out of the wall, any mixer with 150mm centres will fit.

[Andrew Gabriel]

First, check what mains flow rate you get in litres/second by timing filling a bucket or similar, to make sure it's enough to run a shower. If you have a mains tap in the bath/shower room, do the test using that.

I bought a Gainsborough (IIRC) thermostatic mixer which can be surface or flush fitted, so you could surface mount it now, and flush fit it later. My model is no longer available, but some general comments which I picked up when I was choosing...

You _must_ get one which is suitable for a combi (or multipoint) hot water system if you are using it on such a system, i.e. high pressure cold and variable pressure hot. Gainsborough did 3 variants, and one was for this combination (the other two being unsuitable).

There seem to be two types of thermostatic control -- wax phile type which are slower reacting (and I suspect are in the bar type mixers), and coiled bimetallic type which are very fast reacting. The latter type is preferred for a combi/multipoint where you might get other demands on the hot water whilst you are showering, but are more expensive. My Gainsborough is the latter, and I notice no change in the shower temperature when other taps are turned on/off. There are also electronic ones now -- my brother just had an Aqualisa(?) one fitted, but it's too soon to report on the temperature stability (not yet used it).

[Jim Alexander]

Have a look at Screwfix p/n 31693 or BES p/n 14567. These are typical of Italian unbranded bar type thermostatic shower mixers. The spec, particularly the 0.1 bar minimum pressure, is similar to 2 installations I have done, one a combi fed, the other unvented fed. Both have worked well. Lidl does similar unbranded bar mixers once or twice a year for under £30. Makes me think paying more for a poorer spec is a rip-off. As mentioned elswhere hey all have 150mm centres.

Jim A

[Steve Firth]

We've had a Grohe bar shower mixer for several years. They have a good rep. but ours failed this summer dur to accumulation of limescale and it chose to do so just a few months outside the five year warranty. But I've been happy with it right up until the day it failed and I'd have another. If you want cheap there are "Monarch" brand showers available which are identical but cost £50 for the full installation kit. B&Q sell Gainsborough units which are identical to the Monarch range but they cost £150 and IMO that's a rip off.

[John Stumbles]

Exposed bar-type mixer valves almost all seem to be 150mm centres with

3/4" female threads on the valve. The 'traditional' style circular valves have various pipe spacings (I've just measured one I am fitting at 153mm!) and have 15mm compression fittings on the valve (so you need 15mm pipe stubs emerging from the wall).

[smaggs]

Hi Jim, thanks for supplying codes for me to look at - really useful. I like the look of this, but can you tell me if its suitable for the pipes to be exposed? i.e. pipes to come through the ceiling and lay over the top of the tiles, as we're not planning on redecorating/retiling the bathroom for at least a year. Thanks

[Jim Alexander]

The main thing to understand is that bar mixers rely on the rigidity of the supply pipework for their mounting. You could drop down and use a 22mm to

3/4BSP elbow with plenty of PTFE to get alignment, however the mixer would stick out a good couple of inches further than with rear pipework. Shouldn't trouble your plumber if you are happy with the sticky out appearance.

Jim A

[Doctor Drivel]

The good thing about these bar mixers is:

1. If they fail they drip on the shower tray.
2. They are super easy to replace, even with another makers product as the centres are the same.