When I first set up the smart home system I used my iPad as a hub. You don’t need a hub at all for the individual smart radiator valves to follow their daily schedules, but the use of a hub is required for devices to interact with each other (such as a valve calling for the boiler to come on) or indeed to identify which days are working days and which are non-working days (since this is taken from a calendar). However of course this doesn’t work when the iPad is removed from the home.
The solution is to configure an Apple TV box as a home hub – enabling devices to communicate via the TV box. This also enables remote control so a user with an iPad can operate the system when away from the home – such as disabling the vacation settings while still on vacation to allow the house to warm up.
Of course the Apple TV box can also be used to watch TV which my daughter uses to watch CBeebies or YouTube kids TV via the appropriate apps.
To date we have 7 smart devices – 6 radiator valves divided between 4 rooms, and a socket which is used to enable the boiler when any smart valve demands heat.