While you wait for answers, we may have found some information which could help you.
Click here for Help Working Hotcsi 85t ravenheat no power at fan?
Ravenheat CSI 85 Red Light?
Faulty Worscester 35 CDi loosing pressure?
ravenheat csi 85 b (t) hot water no central heating?
minimal hot water ?
ravenheat csi 85(t) 780 series red light flashing?