We may have found other answers which could help you.
Click here for Hot Water Problem Ch Valvevaillant ecoTEC plus boiler fault code - how to fix?
What does f.25 mean?
Vaillant eco plus 531 boiler?
Vaillant vcw gb242 eh central heating problem?
Vaillant 828E - no hot water?
Vaillant ecotec 831 plus?