(See photo) Have a wall I'd like to close up with sheetrock we have lying around, but I've hesitated thinking that with a new boiler installation in the next few years any needed electric wiring would be best done behind the sheetrock. (junction box is on the ceiling in front of the wall, so perhaps wiring behind would be unecessary, whether a wall or floor mount.) Do installers here do alot of wiring behind the wall through the studs for a neater job? From my memory it seems like it's only the main power line we're talking about; all the other circ, etc lines are usually done on the sheetrock itself in BX or conduit.
When possible it is best to have a dedicated circuit for the boiler related controls.
This eliminates the possibility someone trips a circuit and accidentally leaves your heat off.
It is pretty common to have a junction box behind the drywall which has the boiler circuit wiring.
The installer can then mount a box extension and disconnect switch. The rest of the wiring is usually surface mounted.