I'm the original poster and am now quite confused with the differing responses!
The electric shower is a Triton t90si. We moved into the house about a year ago so weren't around when it was installed. I'd say it was installed fairly recently (last few years).
The cord is just outside the door of the shower but inside the bathroom.
Previously, if you turned on/off the cord, a red light would go on/off on the box on the ceiling that the cord ran into.
If you wanted to use the shower, you would pull the cord down to "on" which would light a red switch, step into the shower and then push the button on the shower to get the water running. Once finished, we would push the shower button off and then pull down the cord to "off". The red light would then go off.
If you tried to push the button in the shower without having the pull cord at "on", no water would come out of the shower.
A couple of weeks, we were no longer able to pull the cord down and turn it to "off". The cord is now constantly at "on" with the red light showing.
So, does anyone know what is the purpose of this cord?
Is it a safety cut-off mechanism which should be left on at all times or should it be turned on and off everytime you use the shower?
Thanks again.