UA

Daikin Indoor–Outdoor Capacity Mismatch / Excess Connected Capacity

Daikin multi-split outdoor unit shows UA; some indoor units may not cool or heat

Safety Warning

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

Total indoor unit capacity exceeds outdoor unit rated capacity, Incorrect indoor model combination, Wrong DIP switch or capacity code setting on outdoor PCB, Incorrect system configuration in service mode

How to Fix / Troubleshooting

Safety first: Power off the system before accessing the outdoor unit PCB or DIP switches.

Checks:

List all indoor unit model numbers and compare their total capacity (BTU/kW) with the outdoor unit's allowable connected capacity from the Daikin manual.
Verify that the indoor models are approved combinations for the outdoor model.
Check any capacity or system-type DIP switches on the outdoor PCB and set them according to the installation manual.

Technician actions:

Reconfigure the system in service mode if misconfigured.
If capacity is truly excessive, remove or replace one or more indoor units with compatible models.

Repair Difficulty

Hard 4/5

Required Part

Outdoor Unit Main PCB

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