I struggled with my new hub to pair some old Smartthings devices because I had tossed the manuals. I finally found on the web how to get the devices to re-pair, and thought I could save someone a bit of trouble.
to put in add mode
- remove battery from the device
- start pairing on the phone
- hold down metal ball for reset (I used a thin screwdriver)
- insert battery - light will turn orange
- remove reset while light is on
- light turns blue and blinks
may need to take the battery out and reinsert a few times. Also if it isn’t pairing then hit exit on the phone, when it asks if you are sure hit resume.