Shower Thermostat/Valve Plate

[phykell]

Hi,

My shower thermostat control is faulty but I can’t seem to remove the control knob as there are no retaining screws. I think the knob is turning freely and may have stripped the splines.

The thermostat control is one of three controls on a flush mounted faceplate.

Does this sound like it can be repaired or do I need to replace the entire plate? And how is that control knob retained anyway?

Thanks

 

[phykell]

Just in case anyone is able to assist, it's a "concealed shower valve - 3-way diverter valve". The top control is to switch the flow on, the bottom control is to switch between the overhead shower and the hand shower hose attachment. The middle control is the thermostat.

I saw a video online and removed the grub screw from the thermostat control after removing a small chromed grommet/cover. Unfortunately, the control knob cannot be removed so I'm at a loss as to how I can get at the thermostat cartridge.

Any ideas?

 

[terryplumb]

Post pictures please. If grub screw had been removed , then usually just held on to the spline. They get encrusted with limescale and often have to be " persuaded " off. Pouring very hot water over them may help.

 

[phykell]

Thanks for the reply - here's what it looks like:

By very hot water, do you mean out of a kettle?

 

[terryplumb]

Yes very hot ,it expands the metal handle and may help. You need to remove all three handles and the chrome plate to expose / remove the valve body from its housing. And of course the cold and hot water to the shower must be isolated before removal.