Daikin Indoor EEPROM or Option Setting Error

Daikin indoor unit shows A9; unit may not heat properly

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Corrupted EEPROM on indoor PCB, Incorrect field setting or option code, Wrong replacement PCB installed, Poor PCB connector contact

Safety first: Disconnect power before accessing the PCB.

Steps:

If the PCB was recently replaced, verify that the correct Daikin part number was used for this model.
Check all connectors to the PCB and reseat them.
Reset power to the unit to see if the error clears.

Technician tasks:

Enter service mode and verify or reprogram option codes according to the installation manual.
If EEPROM is corrupted and cannot be reprogrammed, replace the indoor PCB.

Hard 4/5

Indoor Unit Main PCB (EEPROM)

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