its mean the power output the shower. this wll be electrically wired and if you had an electric shower before and the Kw was less then buying an 8.5 Kw shower, might mean changing the wiring to the shower from the Db (consumer unit). If firstly installing then the manufacturers instructions will help you with wire sizes etc.
Kw equals kilowatt hours. Basically, the bigger the KW, the larger the element and consequently the more water can be heated at once so the better the shower.
Showers range from about 7.0 kw up to 10.5 kw with 8.5 being the most common.
A 10 kw shower would use 10 units of electricity in one hour, or 5 units in half an hour etc.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!