The 855 box is not available separately but the 855 control center can be bought from then GB rep of Theben: http://www.timeguard.com/.
On further inspection I am not sure that either the box or the control center can control motorised valves but only provides additional sensors to monitor...
I am also interested in this. In the operating instructions posted below it looks as if you might need the Ramses 855 (http://www.theben.de/fileadmin/downloads/RAMSES_855_top_310_134_02_GB.pdf) to operate weather compensation and the motorised valves. Can anyone confirm ?
Thanks for you help
