Applies To

  • Indoor Unit: ARTG24LMLC

  • Outdoor Units: AOTG36LBLA5 / AOTG45LBLA6 (Multi System)

Issue

When connecting ARTG24LMLC indoor units to AOTG36LBLA5 or AOTG45LBLA6 multi outdoor systems, error code 0023 may occur if the indoor unit’s serial number format does not meet software compatibility requirements.

Root Cause

The indoor unit control board (PCB) version and software coding differ between older and newer manufactured units.

  • Units with serial numbers in the “R0xxxxxx” format use older firmware that is incompatible with the multi outdoor units listed.

  • Updated units with serial numbers beginning with “R1xxxxxx” have revised software that supports multi-system operation.

Solution

To ensure full system compatibility and prevent error 0023, confirm the following before installation or commissioning:

  1. Indoor Unit Serial Number Requirement

    • Must begin with R1xxxxxx (e.g., R114701).

    • Units labeled R0xxxxxx cannot be used in this multi configuration.

  2. PCB and Software Revision

    • Compatible PCB: K06AK-1201HSE-C1 A28

    • Alternate marking on chip: 78AO-KE2-A28

    • Software code A28 confirms the updated firmware version required for multi operation.

  3. Identification

    • The updated R1-series indoor units and cartons are clearly labeled with the new serial number sequence.

    • The change is reflected both on:

      • Carton Label

      • Unit (lated) Label

  4. (Refer to the illustrated comparison provided above showing “Before” (R0xxxxxx) and “After” (R1xxxxxx) labeling.)

Outcome

  • Using R1xxxxxx indoor units ensures full communication compatibility with AOTG36LBLA5 and AOTG45LBLA6 outdoor systems.

  • Prevents Error Code 0023 and related communication issues.

  • Confirms compliance with the new PCB software standard A28.






NEW PCB 2004 on the sticker

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