Can't adjust thermostatic shower mixer

[westhead]

I moved into a property recently and having problems with the shower in the main bathroom. The temperature's always too cold when the dial is turned to the hottest setting. There's scalding hot water getting to the taps and the en-suite shower so I'm assuming the thermostatic shower knob needs adjusting. I can't much info about it online but I figure I need to get that chrome knob off [the middle one in the pic below] and adjust it from there. I can get an alan key in and can feel it turning but can't seem to be able to remove that chrome cover. Can anyone advise? I'm worried using brute force will damage it.

 

[westhead]

OK so I got the chrome cover off - the problem is the valve had snapped off inside the knob [don't know the proper terminology sorry]. It looks like a Victoria Plumbing valve I should replace. Does that sound right?

 

[steadyon]

1. I'm afraid it could be one of any number of shower valves.
2. Send your photos to showerdoc.com and see if they can recognise the make and model.
3. You will need a new valve and a new knob. The knobs are often made of a zinc based alloy like Mazac, and can weld themselves to brass.
4. The spring and pin inside the knob are part of the temperature override mechanism. You set the shower so that with the spring button out, the water temperature at "max" is 38 degrees. You should then be able to push the button in to turn further and get a few degrees hotter water.

 

[westhead]

1. I'm afraid it could be one of any number of shower valves.
2. Send your photos to showerdoc.com and see if they can recognise the make and model.
3. You will need a new valve and a new knob. The knobs are often made of a zinc based alloy like Mazac, and can weld themselves to brass.
4. The spring and pin inside the knob are part of the temperature override mechanism. You set the shower so that with the spring button out, the water temperature at "max" is 38 degrees. You should then be able to push the button in to turn further and get a few degrees hotter wat

Thanks for this, really helpful. I was thinking there's no way I'm getting that brass bit out of the knob.

I was wondering what the spring/pin was for, that makes sense.

I'll see if I can identify the valve then, cheers.