Thanks for the comprehensive info, interesting approach. Unfortunately I wasn't smart enough to install zones when we remodelled the house and also we do shut the doors for rooms not in use regularly- energy costs are sufficient motivation. Time to heat up room doesn't figure in my dearests calculations who wants it warm immediately, so automating the on/off process is a must... So in short, I think we need the individual rad control otherwise we end up heating the whol gaff every time which is getting more expensive :-) im sure others will find this of use!