Thermostatic bar shower mixer - problems and servicing help please

I have an Inta Ion Bar shower mixer. It was bought from Screwfix about 3 years ago, though I can't find the same one in their catalogue now.

It's a standard bar mixer with G3/4 inlets spaced 150mm apart, and one know for flow, and another for temperature.

It has lately become eratic in operation, with the temperature going cold. It is NOT a supply problem, both hot and cold are still adequate pressure and the hot water is still plenty hot.

So my two options are try and fix it, or replace it.

If I look at the installation manual, it says the thermostatic cartridge can be removed and cleaned - for instructions contact Inta.

So any pointers how I remove it, and what to look for to determine if it is just cloged with debris, or actually failed?

Alternatively can anyone reccommend a replacement. MUST be G3/4 fittings 150mm apart (i'm not ripping out the plumbing, re tiling etc) The only ones now in SF are 200mm or 300mm (SF part No's 31693 and 83093) but is that overall width, or pipe spacing centre to centre?

 

That sould be one knob for flow ...

 

It will be the cartridge which has packed up.

I kind of assumed that. My question really was how do I remove it to have a look? Will it be pretty obvious like dismantling a tap once I remove the knob, or is it something really complicated that will spring apart into hundreds of pieces when I remove it, with no hope of ever re assembling it?

I guess it's at least worth a look just to see if just cleaning it will restore it's operation (our water does tend to be a bit dirty at times). Also can I just buy a new cartridge? are they pretty standard or does each make of shower have a different cartridge fitting?

 

Just an update. I contacted the manufacturer today. They told me a replacement thermostat cartridge was £40 plus VAT. I treid to order one, but was told I must order through a merchant.

So contacted my local merchant whom I have an account with, and they ordered it for me, at a cost of £32 plus vat!

Cheaper than replacing the whole thing.

 

More help needed guys.

New thermostatic cartridge arrived today. It looks straightforward, a simple screw in unit. It has 3 O rings along it's length, presumably to seal agains different parts of the body of the bar mixer to separate cold water, hot water and warm water out.

So I unscrew the old cartridge. BUT instead of the whole thing coming out, only half of it came out, followed by a pin, a plunger and a spring. Half of the old cartridge is still in the body of the bar mixer.

Now looking at the new cartridge, it looks like two plastic mouldings that clip together to form the complete cartridge. The old one has unclipped.

Now whatever I have tried has failed to shift the old one. There's not much available to pull on, and in trying this one of the 4 prongs that clip the two parts together has snapped off. I have unscrewed the flow valve (just like a tap plunger) from the other end of the bar mixer hoping to push it out from that end, but no, access is blocked by an internal flange.

So how do I proceed. As far as I can tell there's not much option now but to completely destroy the remains of the old cartridge in trying to free it. I can only assume it is stuck due to crud build up etc. I am not expecting the old cartridge to come out unbroken, it's just that I don't want to damage the body of the bar mixer trying to remove it.

Any advice appreciated.

 

It should just unscrew or pull out but far better to
junk the valve and fit a Mira Coda - great little bar
valve and much easier to service.

I'm beginning to agree with you.

I finally got the rest of the old cartridge out, by rotating it first with a large screwdriver then it finally came out. It doesn't unscrew, it was simply just stuck.

So I have fitted the new cartridge. Boy was it a tight fit. But finally it seated all the way down.

I've just tried it, and blow me down it seems to have the same problem. While it appears to work okay at first, after it's been on a few minutes, if you turn the temperature down, then back up, it stays cold. Turning it off then back on and it seems to come hot again.

So I took it apart again to investigate. Having studied the old valve, it's operating principle is extremely simple. A slider valve connected to a thermally expanding "post" so as the water temperature varies, it moves either left or right to alter the ratio of hot / cold, so in theory keeping the temperature constant.

I can't see anything obvious wrong with the new one, so any ideas what may be wrong?

 

It should just unscrew or pull out but far better to
junk the valve and fit a Mira Coda - great little bar
valve and much easier to service.

Well I took it apart, found nothing wrong and put it back together. This time it works, the thermostatic control is working properly, though for some reason the flow rate is a bit down on what it used to be, but still not bad.

Lots of people on here have sugested the Mira Coda as a better replacement. That has the same 150mm centre fixing, but can someone confirm which is hot and which is cold. On this Inta bar mixer, hot is on the left and cold on the right. Is the Mira the same?