You can display disconnect markers for connectors that are not currently connected.
Check Systems panel
Show Disconnects. In the Show Disconnects Options dialog, select one or more of the following:
Click
Show Disconnects and clear the selections to turn off the disconnect markers.
In the following example, Duct disconnect markers were selected.
Click a warning marker to display a related warning message. Click
Expand Warning Dialog to view the details of the warning message.
In the following example, Pipe disconnect markers were selected.
Click a warning marker to display a related warning message. Click
Expand Warning Dialog to view the details of the warning message.