While you wait for answers, we may have found some information which could help you.
Click here for Hot Water HelloWhat is wrong with my ravenheat white star combination boiler,?
Ravenheat CSI 85 Red Light?
Central heating but no hot water?
ravenheat csi 85 b (t) hot water no central heating?
ravenheat csi 85(t) 780 series red light flashing?
minimal hot water ?