10
Unknown Device Detected
This code typically points to
- New communicating device added after original setup
- Offending device soft-disabled by thermostat
Next checks to confirm
- Confirm wiring between thermostat, smart hub, and devices
- Cycle power
- Reconfigure system
- S30 path: Menu > Settings > Advanced Settings > View Dealer Control Center > Equipment > Reset / Re-configure System
Escalation
Thermostat may soft-disable the unknown device; furnace/air-handler/outdoor controls may show double horizontal lines; damper/EIM green LED may flash 3 seconds on / 1 second off
Reset behavior
Clear by reconfiguring the system.
Service Soon
Schedule repair