While you wait for answers, we may have found some information which could help you.
Click here for Intermittent Hot Waterravenheat csi 85 b (t) hot water no central heating?
ravenheat csi 85(t) 780 series red light flashing?
Ravenheat CSI 85 Red Light?
how can i ignite the pilot light on a ravenheat boiler?
Central heating but no hot water?
csi 85t ravenheat no power at fan?