This example illustrates how to use the heater model that takes as an input the heat added to the medium.
The model consist of a water volume with heat loss to the ambient. The set point of the water temperature is different between night and day. The heater tracks the set point temperature, except for the periods in which the water temperature is above the set point.
See Buildings.Fluid.HeatExchangers.Examples.WaterHeater_T for a model that takes the leaving water temperature as an input.