how do I rectify the fault as detailed below?
my vaillant boiler is saying a code com on it ?
Valiant thermostat , BMU-Err ?
Why is heating on at night?
Boiler over pressure on the hot-water side?
Water dripping from opening at top of pump?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Vaillant vcw gb242 eh central heating problem?
No hot water, intermittent when air temp drops?