Without looking at your model, it seems that there are two possibilities:
- You do not have a bypass branch on the supply and demand side of your plant. These still allow flow to occur in the plant, but avoid components like heat pumps and coils that will exchange heat with the fluid when it's not desirable.
- You have a pump that is operating all the time. Efficiency losses in pumps translate to some heating transferred to the fluid. Whether you're using a constant or variable speed pump, make sure that the
Pump Control Type input field is set to "Intermittent" and not "Continuous".
