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