how do I rectify the fault as detailed below?
my vaillant boiler is saying a code com on it ?
Vaillant Thermocompact Fault?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Vaillant vcw gb242 eh central heating problem?
Hot water comes and goes!?
Hot water supply?
Vaillant condensing boiler ecoTEC plus?
Vaillant igniting issue ( domestic ) not CH?
Why is heating on at night?
Boiler over pressure on the hot-water side?
how to fix water pressure its down at bottom of grey part?