how do I rectify the fault as detailed below?
Boiler over pressure on the hot-water side?
Valliant Eco tec 28?
Valiant thermostat , BMU-Err ?
Vaillant vcw gb242 eh central heating problem?
Vaillant Ecotech Plus 831 F22 fault?
how do I vent the heat exchanger?
my vaillant boiler is saying a code com on it ?
No hot water, intermittent when air temp drops?
Problem with the pressure in combi boiler?
vaillant ecoTEC plus boiler fault code - how to fix?
Hot water comes and goes!?
Advice?
can i replace my Potterton EP2 2 way programmer with a Center EHE0200361 RF?
Vaillant eco plus 531 boiler?