Hi, New home owner here, the house that needs a fair amount of work but I am very comfortable with most projects so no big deal. However I have never had any experience with hot water heat before and have a few questions about purging air from the system. From the direction arrows on the pump and zone valves and the boiler manual the system is as follows: Boiler → expansion tank → main shut off valve → spigot (A) → split into zones → zone shut off values (A) → radiators → zone shut off values (B) → honeywell zone values → merge into single pipe → grundfos pump → Tee with supply line that also has drain spigot on it → boiler Everything is currently working and I have heat but one zone has air in it that I would like to purge out. From what I can tell purging will require closing the main shut off and using supply pressure to push water the reverse direction through the pump and zone valve and then out spigot (A). The honeywell zone values and zone shut off valves (A) could be used to control which zone is being purged. My questions are does this process seem right, and will verse flow cause damage to a grundfos ups15-58fc pump or honeywell V4043 or V8043 zone valves? Any help is appreciated.

instead of running each thing to the main breaker panel, would it make sence to have a main disconnect in the basement feeding a little sub panel that then feeds out to everything chiller, boiler, pumps and fan coils and many more while these things have the disconnects on the units as well like say outdoor chiller disconnect? this way a zoned fan coil will not be running while a circulator is being serviced. or is this overkill?