how do I rectify the fault as detailed below?
Problem with the pressure in combi boiler?
Vaillant igniting issue ( domestic ) not CH?
Vaillant condensing boiler ecoTEC plus?
Vaillant Thermocompact Fault?
how to fix water pressure its down at bottom of grey part?
What does f.25 mean?
my vaillant boiler is saying a code com on it ?
How do I fix f22 error on my Vaillent Ecotec Plus boiler?
Vaillant ecotec 831 plus?
Vaillant vcw gb242 eh central heating problem?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?