http://www.shop.bt.com/products/bt-home-…

Answer:
Bill…Regard your Hub as a phone…for all intense and purpose, that's what it is. You don't unplug that all the time do you. The Hub likes to be left on. it does all its home keeping chores while you're asleep. Please leave it on that's why there's no switch, it costs zilch..certainly less power consumed, than your phone
Answer:
It hasn't got a switch so presumably it is intended to be left on. Even if it had a switch the PSU would still be on even though I think modern PSU work on load (they shut down if no current is being drawn). To be safe it might be better to have all your Personal computer plugs, hub, printer, speakers etc plugged into a multi way. Then at night you can flick off the main socket switch to kill everything.
Answer:
Yes its fine to leave it on 24/7.

But if you can also change settings on it to stop world wide web access during the night if that helps.

I have set mine so it cannot be accessed between 1am - 6am 7days a week. So im safe knowing that nobody can access it while im asleep
It can also be set during the day aswell, so if you at work nobody can access the web, yet it will stil be able to download updates and also your phone line won’t be effected.

type this into your world wide web browser 192.168.1.254 it should then open up the configuration page for your hub. You change all kinds of settings on here.

you might find a bit of info on this website ive just found

http://www.frequencycast.co.uk/homehub.h…

Answer:
I switch mine off every time I’ve finished using my personal,
it saves on power and nobody can access it when its switched off.
and it only takes 2 minutes to work when you switch it on.
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It should be left on all the time, software updates are loaded to it at night
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what’s the problem with it on all the time that’s what we all do
Answer:
Yes it's fine to leave it on 24/7-I've had mine a couple of years now and have never turned it off