My shower has been installed for few years now with no problems. I went to turn my ceiling switch on and a light appears. My shower units light does not appear though. I then turn my shower dial to on and nothing happens apart from my ceiling switch light disappears. Im assuming its a safety switch off, but no other electric goes off and when i turn my shower unit off, the ceiling switch light reappears. Any ideas? Would be a great help, thanks to anyone who helps, Mark