There is normally a sticker on the underside that has the kW rating in small type. If not then there is a rating label inside. The fitting instructions tell you what size wiring and circuit breakers are required so you can fit a larger size if the same wiring and circuit protection will do, otherwise you will need to fit the same size. A plumber will normally be able to tell you if the wiring and protection is ok before he fits the new shower.
Paul M, February 2009
