Hi my name is ***** ***** I will assist you with your query this evening.
Can you advise the model number of the power shower, and what lights come on when it starts emitting water and what lights are shown when it cuts out?
I am struggling to find that model number on the manufacturers website, however this sounds like a pump or valve problem.
Before calling out a plumber I would remove the hose by unscrewing it from the bottom and then turn it on just to prove there isnt a blockage in the shower head or hose.
You would then need a qualified person to remove the electric shower surround (removing the control knobs first), and then inspecting the two valves and water pump, note this needs to be done with the power turned off.
Please let me know you any further clarification as to what you need a plumber to do.
Sorry to hear this was uneconomical to repair, please let me know if you require any further guidance on the matter. Otherwise I would appreciate it if you could rate the service received so I may close the case.