@gohan Didn't think about the hw reset, may incorporate that yet as a belt and braces solution irrespective of the UPS.:+1:
The problem with the Node controlling heating lay with human interface to vary conditions, Home/Away, Top floor occupied/Not, ignore that room as the window is removed as my most hated relative is staying in it... ;)
The possibility for later remote secure external access made the Controller the logical choice with the greatest flexibility.