how to fix water pressure its down at bottom of grey part?
my vaillant boiler is saying a code com on it ?
Vaillant ecotec plus 630?
Problem with the pressure in combi boiler?
vaillant ecoTEC plus boiler fault code - how to fix?
What does f.25 mean?
No hot water, intermittent when air temp drops?
Vailliant turbo max plus 824e?
Vaillant vcw gb242 eh central heating problem?
Vaillant eco plus 531 boiler?
can i replace my Potterton EP2 2 way programmer with a Center EHE0200361 RF?
Advice?
Vaillant igniting issue ( domestic ) not CH?
resetting thermostatat?
how do I rectify the fault as detailed below?