No power in the power shower, what are troubleshooting steps?

I feel there is no power in the power shower. It is otherwise making hot and cold water on turning the knob as appropriate. What are the steps of troubleshooting. I checked the fuse in the mains and fuse next to the switch supplying the power shower. No other electrical or light failure noted in the house. I still wan't to confirm if power is entering into the shower. Need troubleshooting steps please. Thanks in anticipation of helpful answer.