Lennox SLP98UHV Error Code Two horizontal bars: Soft Disable
What Does Code Two horizontal bars Mean?
The two horizontal bars on the Lennox SLP98UHV display indicate soft disable mode. This occurs when the iComfort thermostat detects a device on the BUS communication system that it does not recognize. The thermostat sends the unrecognized device a command to enter soft disable mode until it is properly configured.
This situation most commonly occurs after new equipment is installed or replaced — for example, a new control board, a new outdoor unit, or even a thermostat replacement. The new device appears on the communication bus but has not been registered or configured in the thermostat's device list. Until the thermostat is set up to recognize the device, it keeps the device in soft disable to prevent uncontrolled operation.
Resolving this requires a technician to verify all wiring connections are correct, cycle power to the system, and then go through the thermostat setup process to properly configure and register all devices. The specific path is typically Setup > System > Devices > Thermostat > Edit in the iComfort thermostat menu.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Thermostat does not recognize a device on the communication bus after installation or replacement | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- The system needs to be reconfigured through the thermostat setup menu
- Soft disable appeared after equipment installation or replacement
- You do not have access to the iComfort thermostat advanced setup menus
✓ Verified against manufacturer service manual — March 2026