I have to say my experience with Hive has been nothing but exceptional. All the way from having it installed back in 2016 (when we moved in) to this day when it came on for an hour this morning. The controller is right next to the boiler in the eaves of my house and is connected via ethernet through a TP-Link TL-PA9020P powerline adaptor. In all fairness the thermostat is very close to the receiver, in the landing, so maybe that's why it's never been an issue. I don't think I've ever once had a single issue with using the app, whether that's from downstairs or from the other side of the Atlantic. It will be the first thing on the shopping list when/if we ever move.