I am rolling out zone per room heating controls upstairs, having done this downstairs previously. The upstairs has been a single zone with average temp inputs from all rooms. I need to roll this out in stages, so I've added an HVAC + zone valve to the first rooms and it all works as expected. However to ensure that the remaining rooms still have heating I want the old all-upstairs HVAC and the new per-room zones to be able to call for heat. To do this I converted the upstairs zone valve to a slave valve with the upstairs HVAC and the per-room zone valves as inputs. Cortex didn't like this as with an HVAC object on the input of the slave valve the "add" button didn't work. I removed the HVAC then added the HVAC and zone valves in one - all looked good. Added to this I had configured all the rooms with a heat load and enabled a boiler object to achieve minimum load.
On testing I forced one of the per-room zones on which forced the zone valve and slave on - good. I then removed the call from the HVAC object - the zone valve switched off, but the slave valve stayed on. Even after a restart and switching the HVAC object and the zone valve off, and the boiler object off (not physically connected to the boiler) the slave valve still said the test-room zone was calling for heat, and remained open.
I saved the database and reverted to a back-up (another story).
Any ideas how to get the mixed per-room and multi-room HVACs to work together with a single physical heating zone?