Help, 5 years ago I installed (1st attempt ) a gainsbro' shower. This morning there was a smell of burning and so off it went. I found it had sort of melted inside. It was I think a 8.5 or 9.5 kw I'm thinking of getting the same model but a 10.5 kw so the fitting will, or at least I think so, be the same. will any of the wiring need looking at or should the same wiring apply