Northern Italy, close to Milan... rather cold in the winter, really hot in summer, always damp...

But I often spend days in Tuscany...
back to the topic... Mavis, Top Brake, paulockenden, f1arp72, you're right about the ease of leaving everything "on" or just select the "Off" quick action, and I was actually thinking about leaving my EvoHome alone.
But I always think it's better not to leave on any unused appliance, for several reasons. First, everything that's "off", should not break. Second, why leave an unused electrical device plugged in? It would just consume electricity (not to mention batteries).
One more thing, I read in my TRV manual that it's better to leave them open when unused because the TRV coils would benefit being left open (that means: relaxed) rather than staying close (compressed), even if the HR92s would cycle every two weeks... my valves are oldish and I think it's better not to stress them too much.
As an (almost) unrelated issue, I was planning to call my plumber and have my heating system cleansed this summer. This process involves pumping water through pipes and radiators to chemically remove dirt and then rinse everything to remove the chemicals and debris. I think you need to have all valves open to do this (not to talk of lockshields, and the need of rebalancing next winter

), so I add this on top, as a reason to leave valves open - that I think would imply turning HR92s off or removing them from the radiators...
Anyway, if whatever the reason, I wanted to switch evetything off, am I going to lose the learned info and bindings information? And what about my R8810, would it try to fire my boiler if it wasn't able to detect the controller?