my boiler will no work?
No hot water, intermittent when air temp drops?
how to fix water pressure its down at bottom of grey part?
Valiant thermostat , BMU-Err ?
Hot water comes and goes!?
Boiler over pressure on the hot-water side?
Water dripping from opening at top of pump?
Vaillant igniting issue ( domestic ) not CH?
how do I rectify the fault as detailed below?