Switch on, water runs as usual, cold valve opens after short time as usual, then it goes full bore cold and will NOT switch off.
I have to switch off power at mains and leave off for couple minutes, then it stops.
Blue light is flashing a code of some sort, long, short, etc.

John C., April 2018

Try this site:

https://www.showerdoc.com/shower-spares/aqualisa

Select your exact model and you should find some FAQs and the opportunity to ask a question of your own

You could be a lot more specific about "some sort of code". Set down exactly what the shower is telling you when you post on showerdoc

Fyuigfdd, April 2018