While you wait for answers, we may have found some information which could help you.
Click here for Water Central WorksVaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Vaillant condensing boiler ecoTEC plus?
Problem with the pressure in combi boiler?
Vaillant vcw gb242 eh central heating problem?
Vaillant 828E - no hot water?
how do I rectify the fault as detailed below?