Vaillant igniting issue ( domestic ) not CH?
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?
Why is heating on at night?
No hot water, intermittent when air temp drops?
Valiant thermostat , BMU-Err ?
can i replace my Potterton EP2 2 way programmer with a Center EHE0200361 RF?
how do I rectify the fault as detailed below?