Tap head stuck. Shower valve

[Tony O 1977]

Hi, I've got an issue with temp regulation in my shower. Little to no play, and cannot turn temp down.
I removed the valve, but can't get the tap itself off, the safety button is also stuck down.
Any ideas?

 

[terryplumb]

Is there a grub screw ,maybe under a cover ,on the square handle ?

 

[Tony O 1977]

Yeah, I've removed that.
I'm stumped..
I've got it in water and vinegar to see if that will maybe dissolve some scale and free it but...

 

[terryplumb]

Limescale probably just keeping it stuck onto the spline. Try wd 40 penetrating oil. Stand it on end ,so chrome square on bench ,valve pointing up and spray a load down into it.
Leave for an hour .Tapping the squares edge ,around the periphery with a block of wood may assist in freeing it.

 

[Tony O 1977]

Well.. Tap head never came off, but it's moving far more freely after the wd40! So I've re assembled it all and it's going great guns for now.
Cheers Terry, much appreciated.

 

[terryplumb]

Ha ha , happy showering