This project presents the robust control of time-delay system application to an electronic shower water heater. The aim of the designed is to control the temperature of the water system at the required temperature by users. The designed controller is contained in a small scale microcontroller as a main processor and the controller is also used to generate a PWM signal for drive the heater actuator. To check the performance of the designed controller, we compare the proposed controller with several PID controllers, which are tuned by standard methods. The experimental results confirm that the controller gives better performance than PID controllers in term of settling-time, overshoot. Moreover, the controller is robust to the varying of the initial temperature water input.