While you wait for answers, we may have found some information which could help you.
Click here for Hot Water RsfFaulty Worscester 35 CDi loosing pressure?
Central heating but no hot water?
ravenheat csi 120 no hot water?
Ravenheat CSI 85 Red Light?
ravenheat csi 85(t) 780 series red light flashing?
What is wrong with my ravenheat white star combination boiler,?