Shower mixer valve vs Grub Screw

[cloughy513]

Good Evening all

I'm having a little nightmare with the grub screw on my mixer valve, I can't get it to bite for longer than a day or 2, after this time when I try to turn the valve it just slips making it impossible to change the temperature.

Anyone else experience this issue before any advice, hints, hacks or tips would be most well come currently adjust my shower temp on the boiler very annoying

 

[oldbuffer]

Couple of things to try:
1. Tighten grub screw. Put another grub screw (stainless steel for preference) in behind it and tighten as far as possible. Relatively cheap solution.
2. Remove handle. take out grub screw, clean screw and internal thread carefully. Put back with non-permanent thread seal such as Loctite 243. More expensive.

The above assumes the existing screw can be securely tightened without the Allen key slipping. If not, replace current screw.