I have created a VAV system.

My vav box downstream connectors (multiple duct taps) are set to "calculated" and they dump their calculated values into instance parameters. The upstream connector is preset and sums the downstream connector parameters.

When I first placed these families everything worked great. The flows specified at the diffuser where propagated to upstream the vav box. But when I went back and changed the flow value at the diffuser, the flow upstream the vav box remained the same. The parameters which initially received the "calculated" value will not update. I tried saving and reopening the project, and disconnecting and reconnecting the duct but it will not recalculate.

Any ideas?