Video from Redring water solutions on YouTube - Redring Solutions recommendations the correct sequence to install their Selectronic Premier thermostatic instantaneous electric shower.
The video is full of helpful information from where the plumbing entries and cable entries and inlets are to letting you know where the shower can be fitted, what regulations apply like, BS7671 and Part P. At the end of the video it shows how to use and program the redring Selectronic electric shower.
Enjoy!