Thermostat Says Offline When Changing Temperature

I have a Honeywell Round Lyric Thermostat and am having issues while connected to smartthings. I just got a heat pump installed and have cooling for the first time. I wanted to update my automation temperature control to add cooling setpoints but any time I try to set the temperature smartthings says the device is offline and fails to change the temperature. The thermostat is online and can be controlled by my Honeywell app. After some fiddling I discovered that I can delete and re-add the thermostat and it comes back and registers online until I try to change the heating or cooling temp. I seem to be able to change the fan (auto, on, circulate) without issue. I also found if I go to history and swipe down to refresh smartthings recognizes it as online again till I try to change temp. Finally, when the offline message is showing and the controls aren’t accessible to change, if I use my Honeywell app to change temp or fan, the control updates in the smartthings app “behind” the message but still shows offline. The smartthings thermostat history tracks this as well. I didn’t check recently if this was working before the heat pump so don’t know if this is new or my temp just was never updating overnight like I thought it was. Any ideas?


Wifi thermostats integrations are managed by the manufacturer. If it’s going offline it means the “hearbeat” server , device health, connectivity is having problems. When you change the settings on teh Honyewell app, it sends an update to the ST server and it marks it online. If the Honeywell server stops sendings updates the ST server will mark it offline. This indicates a health system failure on the Honeywell side likely. You’ll have to contact the manufacturer as only they can fix it.