Just to add further information to this:
>Terminal block goes:
>1 white/brown
brown live in on mains lead
>2 light blue and dark blue
blue neutral on mains lead
>3 not used
>4 black/white and Black (t/stat)
240 power return from on/off switch, timer and exhaust thermostat - if your exhaust thermostat is open there will be no power here
Element
>Far left pair terminals - black(t'stat) and black from loom
ring 1 power - if your rear heater (non-resetable) thermostat is open there will be no power here
>Right pair of terminals - red
ring 2 power - if your low heat is turned on there will be no power here
>Single terminal - blue from reset stat
neutral return via resetable thermostat - if your resetable thermostat is open there will be no link to neutral
also the thermostat wires can vary in colour due to source, in my case I have orange leads going to the rear heater (non-resetable) thermostat
Bill A, July 2007