I purchased a surface mounted timer for my immersion heater which will fit a standard 32mm deep socket box, so it seemed a very easy task to replace the standard on/off switch with it. In theory it is a simple job but I only have L,N & E going into existing switch whereas the instructions for new timer switch ramble on about live/neutral output to appliance etc. The immersion has a dedicated fused power supply. Presumably I only need to connect the E cable to the box terminal and the L & N to the relative blocks on the timer. But which ones are the relative terminals? I suspect that I simply connect the L & N to blocks 3 &4, BUT what bothers me is that the cables wired into both of these is blue whereas blocks 1 & 2 are wired red! Timer spec link below, any guidance much appreciated.
http://www.greenbrook.co.uk/pdf/T69.pdf
http://www.greenbrook.co.uk/pdf/T69.pdf