Problem Thermostatic shower cartridge

[bobgroups123]

Hi,

Newbie needs soem help please... i got a shower wall plate with shower diverter knob at top and thermostat knob below.

The thermostat knob is dripping..... I took off the knob and can see the head of the thermostat cartrdige. I dont know the brand and it's not on the plate as fitted 12yrs ago and i never kept the receipt... i do reckon it's Bristan only because wash basin in bathroom was bristan but i cant be sure


Anyway:

1. Why would a thermostat cartridge drip? I thought only the diverter cartridge should drip. Is it possible there is some scal build up on the termostat cartridge and i can somehow clean that off or retighten the cartridge.

2. how do i take off the cartridge - I replaced the diverter cartridge above and that was relatively easy for me using a box spanner... cant for the life of me work out how this thermostat cartridge comes out? Do i prise off the white plastic that just at the bottom of the spline? Once i take it out i can try and see where i can get a replacement or see if i can work out why dripping

please see bottom cartridge on below pic - with the white plastic washer...

Thanks

 

[Basher]

I believe the diverter is connected after the thermostatic cartridge - ie H & C go into thermostat, single mixed output goes into diverter, and then to where you want it.
Therefore water pressure in thermostatic cartridge all the time.

At its base I see an annular ring with a slot in it, presumably one the other side as well. So there was probably a tool with 2 prongs to fit. But the consensus these days seems to be to put a suitable screwdriver in the slot, angle it down and tap repeatedly to undo the ring.

Once you have the cartridge out a plumbers merchant, or shower specialist on the internet, can probably identify a suitable replacement.
Maybe someone here will recognise the brand from your photo's. There seem to be lots of lookalikes on the web, but none I've seen with the same configuration of brass behind the front panel, not really surprising if it's 12 or so years old!

Similar, but not the one! https://images.victorianplumbing.co.uk/images/PDF/AZGMSV.pdf

 

[bobgroups123]

Thanks @Basher

Is this the sort of thing i could take out and put back in if i cant get a replacement straight away?
I got my confidence from replacing the diverter - a bit nervous as this looks different esp all those fittings at the top of the spline... i guess if i do manage to take it out and need to remove anything i better take some photos or a video how it orginally was.

Is a typical fault symptom these things dripping? Also when i turn it i cant get only cold water in the shower. It's just very warm or too hot. Even when it was working it was jut the drip and temp varied ok i.e. cold to very hot.

 

[Basher]

Thanks @Basher

Is this the sort of thing i could take out and put back in if i cant get a replacement straight away?

Yes, assuming you are confident/competent to remove it and replace it without damage.

I got my confidence from replacing the diverter - a bit nervous as this looks different esp all those fittings at the top of the spline... i guess if i do manage to take it out and need to remove anything i better take some photos or a video how it orginally was.

good idea

Is a typical fault symptom these things dripping?

I can't comment. Not 'typical', but given the age of it, perhaps not unexpected.

Also when i turn it i cant get only cold water in the shower. It's just very warm or too hot. Even when it was working it was jut the drip and temp varied ok i.e. cold to very hot.

Part of the hardware you will need to remove is a semicircular stop that limits the travel of the control knob to cover the correct range of temperatures. It needs setting up after you remove this knob. If not au fait with this, you might like to get someone in to do the repair.