We may have found other answers which could help you.
Click here for Vaillant Combi BoilerVaillant 828E - no hot water?
Vaillant vcw gb242 eh central heating problem?
Hot water comes and goes!?
how to fix water pressure its down at bottom of grey part?
What does f.25 mean?
vaillant ecoTEC plus boiler fault code - how to fix?