Hi. We are moving house, so want to take the Evohome system with us. We have a Vaillant combi boiler, with the BDR91 relay attached. Our plumber installed this originally, but now I want to put back the originally Vaillant wireless relay. I just wanted to get clarification on the wiring side of things. The original Vaillant relay was fed by a two core cable with brown and blue wires (live and neutral presumably). The plumber replaced this cable with a four core cable of brown, black, grey and earth cables. The BDR91 relay is wired up as per the attached image. So there is a black cable going to 'N', and a grey cable going to the first 'L'.
Now I am presuming that the black cable 'N' is equivalent to the blue cable in the original relay (neutral), and the grey cable is equivalent to the brown cable in the original relay (live). Do you think this is a reasonable assumption?
http://www.mhriley.com/IMG_6451.png