CT101 thermostat - no longer pairing after switching to new app

After switching to the new app I noticed my CT101 thermostat stopped responding. I can delete it (via the normal exclusion process), and add it again, but when adding it I get the message -

“Some security features not supported - Your device has been connected, but it isn’t using the highest level of security. Use a newer Z-wave device for the highest security”.

The thermostat is then added as a generic Z-wave device (with no controls visible in the app). If I go into the IDE interface and change the device type to a Z-Wave thermostat, it shows the relevant controls in the app but nothing is controllable (and no temperature information is displayed).

I’ve also noticed that the ‘route’ shown in the IDE goes via some ‘Unknown Device (14)’ device, which I don’t see in my device list.

Anyone had similar issues? I’m using a Gen 2 hub.

Steve

Looks like you have a “ghost” zwave device. There’s some instructions here how to get rid of it
https://community.smartthings.com/t/faq-zwave-repair-not-working-how-to-fix-error-messages/18400/105

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 network

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 Thermostat Device Handler with Z-Wave Plus