Vaillant igniting issue ( domestic ) not CH?
What does f.25 mean?
No hot water, intermittent when air temp drops?
how do I rectify the fault as detailed below?
Valiant thermostat , BMU-Err ?
Vaillant 828E - no hot water?
Vaillant 630 error f 85?
how to fix water pressure its down at bottom of grey part?
How many factors causes f22 fault?