While you wait for answers, we may have found some information which could help you.
Click here for Heating Boiler Ravenheatpressure dropping on openning the hot water in my ravenheat csi 85 aboiler?
What is wrong with my ravenheat white star combination boiler,?
Faulty Worscester 35 CDi loosing pressure?
Faulty Ravenheat condensing boiler?
ravenheat csi 85(t) 780 series red light flashing?
minimal hot water ?