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?
Vaillant eco plus 531 boiler?
how to fix water pressure its down at bottom of grey part?
Vaillant vcw gb242 eh central heating problem?
Vaillant condensing boiler ecoTEC plus?
vaillant vcw gb 282gh?
No hot water, intermittent when air temp drops?
Vaillant VCW-Sine18 T3WFH Lights but then goes off after 5 Min?
Hot water supply?