ANDREW & HILARY MEREDITH
You need a plumber to connect it to the water supply unless you do that yourself. But to connect the wiring you need an electrician because it is in a wet area and the regulations require that someone qualified does it. As well as making sure the wires are properly connected, the electrician will tell you whether they are thick enough. If the shower you want to use says not more than 8.5 kilowatts on it, you can use 6 square mm cable; but if that's what you've got at you want to upgrade to a more powerful shower such as 10 kilowatts, you will need 10 sq mm supply cable and if you haven't got that the electrician will have to install it, and that will be expensive in both labour and materials. But it will be nice and warm when it's done!
