Not all smart systems are terrible, I've the Honeywell evohome system and it has been flawless for the 18 months or so that it's been installed, bit it looks li

Not all smart systems are terrible, I've the Honeywell evohome system and it has been flawless for the 18 months or so that it's been installed, bit it looks like a different strategy was used - the main thermostat/bridge/controller is linked via wifi, but everything else is run over a different RF standard, so all the TRV's, thermostats and the boiler controller talk to the main controller directly (iirc it's in the 900MHz range) The main controller runs the scheduler and is the only device which reaches out to the internet (to sync with honeywell's cloud systems so you can control heating etc from an app remotely when away from home). Other than the interface on the controller being a bit clunky, I've no complaints, even the batteries in the TRVs seem to be lasting well.