We may have found other answers which could help you.
Click here for Heating Hot Water BangingVaillant ecotec 831 plus?
Vaillant condensing boiler ecoTEC plus?
how to fix water pressure its down at bottom of grey part?
Vaillant vcw gb242 eh central heating problem?
Vaillant eco plus 531 boiler?
Vaillant 828E - no hot water?