CT101 thermostat - no longer pairing after switching to new app

That means it didnt’ pair properly with the hub (it’s losing packets in the mesh during the pairing process). These thermostats are little picky about the pairing process. I’ve found it best to bring the thermostat within a few 5ft of the hub and then pair it and it should pick the device handler automatically thereafter.

As for the unknown device, its’ a ghost device which should be removed using these instructions: FAQ: How to remove ghost devices from your z-wave and zigbee networks

You can also check out this custom Enhanced Z-Wave Thermostat DTH which supports CT-101 (and other) models and allows you to configure their advanced features: [RELEASE] Enhanced Z-Wave Plus Thermostat Device Handler - Honeywell, GoControl, CT, Linear, Trane, MCO, Remotec