I have been using Google Home with both Google Devices and "works with Google" devices for several years without a problem I couldn't solve, or find a solution for.
Within the past six months or so, a Honeywell Wi-Fi thermostat has appeared under my list of devices. Since I started using Google Home, I've had the same thermostat, I normally control it directly from the Honeywell App. I'd like to be able to control it through Google Home.
I can't remove the thermostat from within Google Home, the icon is "greyed out" - it says "offline" on the center of the icon. I can select "unlink from Google Home", but it doesn't remove the thermostat. When I go to Honeywell's site, Total Connect Comfort, the thermostat isn't listed in my account, I have been able to add the same thermostat to both my Honeywell Account, and my Google Home account, but I still can't remove this "phantom" thermostat.
I'm hoping for help finding a solution to remove this thermostat from Google Home account.
Sorry to hear that you're having troubles removing your device from your Home app and your list of devices, I know it can be confusing but I'm happy to help.
While we don't have a way of removing the device manually, it does fall off after 60 days of being offline and greyed out.
Please let me know if you have any other questions.