drayton digistat 1

[the-trier]

I'm changing my thermstat to the to the drayton digistat 1 and the drayton I want to take off has 4 wires, yellow which is attached to a numeber 3, red attached to (L), blue attached to (N) and the earth which is attached to the casing, the drayton digistat 1 has 3 places for wires to go but they are just numbered 1, 2 and 3, the picture on the box that came with the thermostat tells me 1 = common, 2 = heating satisfied and 3 = call for heat. my question is what colour of wire goes where

[Disco Fever]

1=red live from the timeclock
3=yellow is the live back to the boiler telling it that you require heat.

The earth is of course earth and the blue is neutral but some stats don't need the neutral....