BAC/BMS and their interaction with HVAC equipment

[Sergroum]

Good day.

Would anyone have any good sources of knowledge regarding these issues?

Periodically, I'm thrown to fix hi-rise boilers and that's no problem. But sometimes it's difficult to figure things out when boilers are working perfectly in local setting, but the moment I shift them to remote,  some boilers start just fine, while the other simply refuse to start up. Is the issue in some sensor that the BAS has access to, while the boiler doesn't? Is the issue in the logic of BAS?  Some relay burnt out in the BAS module?  I'm being a little stumped in these instances.