For some odd reason, my custom return air terminals and equipment do not provide the ability to create return air systems. I can't figure out why this would happen. The families list under the Unassigned Systems for Default Return Air in the system browser and I can connect duct to them. However, I can neither create return air systems with the families nor add them to existing return air systems. When I try to add them to an existing return air system I get an error message that says the family doesn't have the matching return air connector for the selected system. This is obviously not true, since they list under default return air and connected ducts color correctly based on my return air system filters. I edit the family to double check and the connector is set to Return Air.
OOTB families work correctly. So is there a button I've pushed to disable this function in my custom families? Anyone seen this?