We have a 4 year old Vokera Combi boiler. The system overflow runs most of the time (steady but slow). The boiler pressure does not drop, and in fact the system pressure slowly rises over a day or...
"Chasing in" wiring in a wall, an engineer has refused to conceal some new wiring, and made it surface mounted because he says Horizontal chasing in of wiring is not allowed, but it would have be OK...