Electric shower

[egginyourface]

Hello all
Went to a call out today where shower would heat water fine on medium setting but once it was set to higher temp it would cut out. Mcb remains in and supply still present. Is there some sort of cut out inside shower if the water pressure is low?

First time I've seen such A fault

 

[Philpot]

I did hear of some one that changed the shower head to one with too few holes.

 

[i=p/u]

i have been here reading abot these before , if it worked fine before then change the shower.. there is a few things to check i.e solinoid valve and we cirular things on top of eleements and after that its cheaper to change like for like and no plumber involved