Try this link for some info ..
https://docs.google.com/viewer?url=https://www.siemens.be/cmc/upload/cms/docs/sbt/hvac/Brochures_Datasheets_manuals/FR/01_Thermostats/Datasheets/N3072_RDJ10RF_EN.pdf
Copy n paste these links into your browser!
Plus one is for sale now on EBAY at this link
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=140373301601&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en#ht_5711wt_1139
I am having problems too as I can not seem too tune both units in for some reason but I have lost the instructions lol
Also the pdf siemens file link I sent you does not tell you exactly how too do it!
Hope my info helps you my friend!
AndyC in UK
November 2010