Hi Ive been buying the evohome components as I can afford them. I now have the 'Connected thermostat pack', 1 x ATC 928 and 1 x BDR 91. I also have 8 of the HR92 valves. My question is can I install these components as the first stage in a full Evohome system, and control the opening and closing of the valves ? All advice appreciated!