Files attached.
CentralInstantaneousWithDHWLOOPBug.zip
This project uses LargeInstantaneous heaters DHSYSs "dhwsys-DHW Gas" and "dhwsys-DHW Gas OtherZns". Both have DHWLOOPs. The "dhwsys-DHW Gas" is not a central system and it appears to run OK. "dhwsys-DHW Gas OtherZns" is a central system and it generates dhw energy balance errors. When the DHWLOOP is omitted, the errors disappear.