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Lennox · Furnace

E105 Device communication problem

High severity EL296UHVLennox SL280UHVLennox SL297NV

What the control is telling you

No other devices detected on the RSBus; many message errors, usually from electrical noise.

Applies to: EL296UHV(X) series furnaces (integrated control 103130-XX and 107045-XX)

Likely causes

  • Electrical noise on the RSBus
  • High-voltage wiring run next to communication wiring
  • Miswired or loose connections between thermostat, indoor and outdoor units

Test and repair steps

  1. Check all RSBus wiring between thermostat, indoor unit and outdoor unit for miswiring or loose terminals.
  2. Separate high-voltage wiring from the RSBus communication wiring.
  3. Look for a nearby high-voltage noise source and relocate wiring away from it.
  4. Cycle power and confirm the code clears once communication is restored.

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Source: Lennox EL296UHV(X) Unit Information / Service Literature, Table 5 Ignition Control 103130-XX Diagnostic Codes, p.33; Ignition Control 107045-XX Diagnostic Codes table, p.40. Summarized in our own words; check the original manual for your model.

Homeowner looking at this code? See what it means for you and when to call a technician.

For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.