While you wait for answers, we may have found some information which could help you.
Click here for Losing Water PressureFaulty Worscester 35 CDi loosing pressure?
ravenheat csi 120 no hot water?
What is wrong with my ravenheat white star combination boiler,?
minimal hot water ?
ravenheat csi 85(t) 780 series red light flashing?
Faulty Ravenheat condensing boiler?