ErrorCodeDoctor
Daikin Air Conditioner UA error code
The UA error means your Daikin air conditioner detected a mismatch between the indoor and outdoor units. This can be caused by connecting units of incompatible models, an incorrect power supply, a wrong PCB, or the outdoor unit PCB settings not being completed after a PCB replacement. Contact a qualified technician to verify the unit combination and settings.
Common causes
- Excess of connected indoor units beyond the outdoor unit's capacity
- Defective outdoor unit PCB
- Mismatch of the refrigerant type between indoor and outdoor units
- Outdoor unit PCB field settings were not carried out after replacement
How to fix it
-
1
Contact a qualified technician to verify the unit combination compatibility and PCB field settings
Related Daikin Air Conditioner error codes
A0
An external protection device connected to the indoor unit has been activated
A1
A fault was detected in the indoor unit PCB (control board)
A3
The drain level control system has detected an abnormality — drain may be clogged
A5
Freeze-up protection (cooling) or high pressure control (heating) has activated — check the air filter
UA error — frequently asked questions
What does the UA error mean on a Daikin air conditioner?
An improper combination of indoor and outdoor units was detected
What causes the UA error?
The UA error is usually caused by: Excess of connected indoor units beyond the outdoor unit's capacity; Defective outdoor unit PCB; Mismatch of the refrigerant type between indoor and outdoor units; Outdoor unit PCB field settings were not carried out after replacement.
Can I fix the UA error myself?
This is rated a hard fix — it often requires tools, parts, or experience, and may be safer left to a professional technician.
How much does it cost to fix the UA error?
Fixing the UA error on a Daikin air conditioner typically costs $80–$300, depending on parts and whether you do it yourself or hire a technician.
Is it safe to keep using my air conditioner with the UA error?
We'd recommend addressing the UA error before continuing to use the air conditioner, since hard-rated issues often involve a real fault rather than a minor glitch.