While you wait for answers, we may have found some information which could help you.
Click here for Water Coming CheckGainsborough 2000x leaking from bottom of copper cylinder ?
Gainsborough 8.5e ?
what KW is my Gainsborough ps1200 power shower as I need to replace it? Any?
How do I remove the hose from my Gainsborough Energy 2000 shower?
Gainsborough Energy 2000x shower stopped working?
Gainsborough 9.5 on/off switch repair?