Soft Disable — iHarmony damper control or EIM

What does Green LED blinking 3 seconds on, 1 second off mean?

On an iHarmony damper control module or EIM, a blinking green LED (3 seconds on, 1 second off) indicates the device is in soft disable mode, likely due to configuration or communication issues.

• Device replaced and needs reconfiguration
• New device detected on the system
• Existing device not communicating with the thermostat

Click steps to track your progress.

1. 1

   Confirm all wiring between devices, including the thermostat and Smart Hub, is secure.

2. 2

   Cycle power to the Lennox system by turning it off at the breaker for 30 seconds, then back on.

3. 3

   Navigate to the thermostat menu: > settings > advanced settings > view dealer control center.

4. 4

   Select 'Equipment', then 'Reset', then 'Re-configure system' and confirm.