While you wait for answers, we may have found some information which could help you.
Click here for Star Combi BoilerFaulty Ravenheat condensing boiler?
ravenheat csi 120 no hot water?
ravenheat csi 85 b (t) hot water no central heating?
minimal hot water ?
Central heating but no hot water?
how can i ignite the pilot light on a ravenheat boiler?