The present invention provides a control system suitable for use with a bathing unit system having a water receptacle. The control system comprises a heating module, a power source and a controller in communication with the heating module and the power source. The power source includes an energy storage member for storing energy collected from a solar panel, and is operative for supplying power generated from solar energy to the heating module. The controller is operative for causing the power source to supply power to the heating module at least in part on the basis of first information derived from a temperature of the water within the water receptacle and second information derived from a condition associated with the power source. The controller is further operative for selecting between a first power source and a second power source for supplying power to the heating module.