While you wait for answers, we may have found some information which could help you.
Click here for Ravenheat Hello Gas Valveravenheat csi 85 b (t) hot water no central heating?
Ravenheat CSI 85 Red Light?
pressure dropping on openning the hot water in my ravenheat csi 85 aboiler?
ravenheat csi 85(t) 780 series red light flashing?
Faulty Worscester 35 CDi loosing pressure?
minimal hot water ?