While you wait for answers, we may have found some information which could help you.
Click here for Couple Hours ErrorFaulty Worscester 35 CDi loosing pressure?
ravenheat csi 120 no hot water?
csi 85t ravenheat no power at fan?
Central heating but no hot water?
ravenheat csi 85(t) 780 series red light flashing?
how can i ignite the pilot light on a ravenheat boiler?