If the temperature timer button works, make sure you set the temperature with the wheel. Then click the button and set the timer. Once this is done, press the play button ... If you do not hear the motor, it is defective and you should return it.
To the right of the lower, smaller display, there is a button. When you press it, you switch between setting the cooking time and setting the temperature. You change the value by turning the wheel on the right.
Both settings are made in the smaller display; the larger display always shows the current water temperature.