ErrorCodeDoctor
Daikin Air Conditioner U6 error code
The U6 error means your Daikin air conditioner system detected a communication failure between indoor units in a multi-split configuration. This can be caused by faulty wiring or external electrical noise, or a defective indoor unit PCB. Contact a qualified technician to inspect the indoor unit transmission wiring.
Common causes
- Faulty wiring between indoor units
- External electrical noise interference
- Defective indoor unit PCB
How to fix it
-
1
Contact a qualified technician to inspect the indoor unit transmission wiring and PCBs
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
U6 error — frequently asked questions
What does the U6 error mean on a Daikin air conditioner?
A communication fault was detected between multiple indoor units
What causes the U6 error?
The U6 error is usually caused by: Faulty wiring between indoor units; External electrical noise interference; Defective indoor unit PCB.
Can I fix the U6 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 U6 error?
Fixing the U6 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 U6 error?
We'd recommend addressing the U6 error before continuing to use the air conditioner, since hard-rated issues often involve a real fault rather than a minor glitch.