Lennox Air Handler: Two horizontal lines on display (soft disable) – Lennox communicating

Two horizontal lines on display (soft disable) - Lennox communicating on a Lennox air handler: The control shows two horizontal lines on its 7-segment display (damper module or EIM: green LED 3 s on / 1 s off). The thermostat found a device it does not recognize and put it in soft disable; the thermostat itself shows no alert code for this (often alert 10 is logged).

Homeowner with a air handler problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Applies to: Lennox communicating air handlers and EIM-equipped indoor units in S30/S40 smart thermostat systems

Common causes of two horizontal lines on display (soft disable) - lennox communicating

• Control board was replaced and the system was not reconfigured
• New device added after commissioning
• Device on the bus not communicating with the thermostat

How to fix two horizontal lines on display (soft disable) - lennox communicating: step by step

1. Confirm wiring between all devices (thermostat/smart hub, indoor, outdoor, damper module, EIM).
2. Cycle power to the control that shows the soft disable.
3. Reconfigure. S30: go to Menu > Settings > Advanced Settings, open View Dealer Control Center, then Equipment > Reset All Equipment. S40: go to Menu > Settings > Advanced Settings, open View Service Support Center, then Equipment Setting > Reset and pick Reset HVAC Equipment.
4. Run the thermostat setup again so it auto-detects every device.
5. Check the device's installation/setup guide if it stays disabled.

If the unit shows an error code, look it up: Lennox Air Handler codes