I'm replacing a shower pump unit (Ideal-Standard Trevi Logical, which is now obsolete) with an identical unit which I purchased on Ebay. I believe the purchased unit is brand-new and unused, though may have been sitting in its box on a shelf for years. The swop-over was straight forward but the impeller on the pump appears to be jammed (can't be revolved by hand). The shower operates via a hand-held remote control which diagnoses "Flow control motor is not working" when ON button is pressed.
I'd be grateful for any advice on whether there's anything I can do to 'unjam' it or do I need a professional to take a look at it ?