WATTS, bath mixer, unable to regulate, bimetallic, NIGHTMARE / tales of oddities

[Ted808]

Applogies guys it's a long story.......
Fella has a bath/shower mixer- apparently a fancy one that was second hand. He's an antique dealer.
Problem is water is too cold to run a bath- thermostatic cartridge right? After some faffing I got hold of manufacturer and dismantled body removed cartridge - which turns out to be bi-metallic strip type. Replacement from local specialist merchant - eye watering -500 squid. Take the unit back put it together and it doesn't work- just no H water flow - so I take another look and new part requires H+C to be opposite way plumbed in. (H-right/C-left) SO I called merchant and asked are some 'cartridges' orientated opposite way? Of course it's a long time wasting , brain draining call back - find out- email - NO. Now by this time I'm well miffed as this is not going according to plan. I seem to be sit job magnet.
Fella has lost his congenial look and now I can see his eyes watering cuz he's adding up my cost plus the part and it's not what he bargained for.
Nothing for but to rip up a tongue and groove floorboard to access pipes below floor and swap them. Always in the awkward place under the bath- but hey ho it went better than I thought and a small stroke of luck it was plastic pipe. Job's a good one- until I test .... better flow but water is warm and until you want it hot- then it shuts off the flow. Ok so now I'm thinking I missed something- all the other H taps are ok, so's the other shower. It's a megaflow- so plenty HW ....if i had hair I'd pull it out!! What is going on? I left...need to think it through, nightmares about it last night and am studying the PDF manuf sent and any other bits I can find online- NO clues as yet. You can't adjust the temp setting on bi-metallic they are just there. YOU can adjust the limiter, but I hadn't even attached that when testing. DID i ruin the 550quid thing when I had it plumbed in the wrong way around initially? The manuf WATTS industries- model ultramix TX93 ANY wise words of advice? Here's a couple of pics..

 

[Chalked]

Unbalanced cold overcoming the hot?

 

[Ted808]

Unbalanced cold overcoming the hot?

maybee...
How did it work before? Would restricting the flow with the full bore ballofix work? I did try this but it seemed to make no difference at all.
I'm going to take a look at the megaflow, maybe there's something going on there. Fella said he has it serviced annually, but I've never known anyone who does.

 

[S.P.S.]

I would guess in-balanced hot/cold aswell. Is this thing designed to operate at 3 bar...???

You may have to install pressure reducing valves to bring pressure down and equalise?

Tricky one

 

[Chalked]

Hers some instructions.
Looks like you can order the mixer with hot and cold both ways.
http://www.wattsindustries.com/images1/wif/doc/d_ultramix_TX93_gb.pdf

Advanced water sell it for £260

 

[Welder]

Looking at the PDF Chalked linked to, the pressure difference tween supplies is 1.5 bar max. This suggests to me that it needs a pressure equalising valve fitting so long as neither hot nor cold exceed 3bar.
If you need one, I can send you one that fits inline FOC. I have a few in 'stock'. Long story 😵
You ideally should fit as close to the inlets as possible but from what you've described you can do that under the floor.
Just DM me if you want one.

Here's a link to what it is. DO NOT use two sep PRVs.

Lastly, and vitally, do not worry about not knowing about them. This gear is all French. No plumber in the UK can be criticised for not knowing what the french do!!

 

[Ted808]

Thanks GUYS for all the pointers- I'm going back tomorrow. I will check the water pressure from the outlets- see if there's something gone wrong there. Before I rush out and put reducing valves in. I wish I hadn't rushed out and bought the blinking thing for 500 squid but hey ho- don't think i can return it... maybe. I'll keep you updated.

 

[Ted808]

A few other bits- yes it's ok for up to 10bar SPS
Cheers YorshireDave you are right it is French!
And lastly the supplier- London Water company also wanted to sell me the whole unit- not just the bit Chalked said from Advance Water 4£260! AND they had a 4 week wait!!
Plan is to check the UHWC maybe the PRV is faulty. (I have G3)
Before that I plan to measure, flow and pressure at tap outlets before 'cartridge'- I'm guessing I have to prove cartridge faulty by eliminating all other possibilities?
Any other suggestions, that I can measure/check?
cheers 🙂