how do I rectify the fault as detailed below?
vaillant ecoTEC plus boiler fault code - how to fix?
my boiler will no work?
Vaillant ecotec 831 plus?
Boiler over pressure on the hot-water side?
How do I fix f22 error on my Vaillent Ecotec Plus boiler?
Vaillant F22 fault?
how to fix water pressure its down at bottom of grey part?
Vaillant igniting issue ( domestic ) not CH?
Vaillant ecotec plus 630?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Problem with the pressure in combi boiler?
Vaillant 828E - no hot water?
my vaillant boiler is saying a code com on it ?
how do I vent the heat exchanger?