Wireless room stat wiring problems

[agiannop]

Hi everyone,
I want to change my digital programmable room stat (Siemens REV100) to the wireless model (Siemens REV23RF/SET). I am having trouble with the wiring and the connection diagram does not help a lot. Here is the wiring situation for my old digital programmable room stat.

And this is the inside of the receiver part of my new wireless stat set

So I guess the permanent live (L) and the switched live (L1) will go to their designated spots as in the old thermostat. However as you see in the picture there are also the N, LX and L2 connections. I still got the earth, a blue (neutral?) and a black (not live) wire coming out of the wall. So I connected the blue wire to N. The receiver came to life and started blinking. I followed the instructions, paired it with the wireless stat and tested. Unfortunately even though the "heating" icon appeared onscreen, the radiators never got warm.
Any ideas?
By the way here is the wiring diagram

Thank you all and sorry for the large pics, I did resize them, don't know why they're still XXL!

 

[Biggles..]

Black to LX should finish the job, wireless stats require a feed(perm L an N) for the transponder side then the themostat connection between switched live and its path back to the boiler.

 

[agiannop]

Well, thanks lcgs and everybody who thought of a solution, I figured it out:
LX does need a live feed which I did not have since I 've got only 1 live wire which went to "L". So I bridged L and LX with a small wire and voila! Finally works! Time to go to bed...