Might be of interest http://www.electricalsafetyfirst.org.uk/mediafile/100145109/web_usb-article-from-so32.pdf I decided against them after reading this a while back.
I don't like the fact you can't switch off the USB part either, seems mental.
Just installed the new Hive 2 smart thermostat and have a question on how to disconnect the old wired Siemens dial-type thermostat. I believe I have an S-plan heating system with a boiler in the garage and cylinder and pump etc in a cupboard upstairs.
Right now the heating only comes on when...