We may have found other answers which could help you.
Click here for Hot Water SignalVaillant 828E - no hot water?
Vaillant F22 fault?
how to fix water pressure its down at bottom of grey part?
Vaillant condensing boiler ecoTEC plus?
Vaillant ecotec 831 plus?
vaillant ecoTEC plus boiler fault code - how to fix?