Modeling a Passive Heat Exchanger in EnergyPlus

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Hi,

I'm using EnergyPlus to model a Fluid-to-Fluid Heat Exchanger on the demand and supply sides of two different loops. However, when I set the control type to UncontrolledOn, it requests flows and overrides the existing flow in the branch. Does anyone know which control type would allow the heat exchanger to operate as a passive unit without requesting flow? Thanks