An interactive multimedia education program has been developed to study the transient behaviour of an active solar heating system for domestic hot water production. The users can explore various cases, study what happens under different operating scenarios and examine the effects of altering conditions. In addition, simulation processes are used when a more quantitative understanding of the related subjects is needed, as they offer higher perceptual fidelity (i.e., more accurate representation of the situation being modelled). The simulation accounts for a large number of parameters and can be used to investigate their effects on the thermal efficiency of the solar collector and the system. It can also be used for an extensive set of exercises in the tertiary education sector. The operating principles and performance aspects of the different components have been considered providing a basis for understanding the components interaction and total system performance. The program is a user friendly, fast, easy-to-use and a powerful educational tool