Error Code: EC 51 – Outdoor EEPROM Parameter Error
What this means:
The outdoor PCB’s main control chip is not receiving valid feedback from its onboard EEPROM — the chip that stores critical configuration and operating parameters. Without this data, the system cannot operate properly.
Try this first (quick reset):
Turn off the power supply to the unit.
Wait at least 2 minutes.
Turn the unit back on and check the display.
If the error clears — the system is operating normally.
If the error remains — proceed to replacement.
Next steps (for technicians):
For EC 51 → Replace the outdoor main PCB.
(Note: EH 00/EH 0A use the same process, but for the indoor PCB.)
What you might need:
Outdoor main PCB (specific to your model)
Multimeter or scope for communication signal confirmation (optional)
Helpful tip:
The EEPROM (Electrically Erasable Programmable Read-Only Memory) is a built-in component on the PCB and cannot be replaced separately. The only fix is replacing the entire board.
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