ErrorCodeDoctor
Daikin Air Conditioner C1 error code
The C1 error means your Daikin air conditioner detected a communication failure between the indoor unit main PCB and its sub PCB. This is caused by a defective connector connection between the two boards. Contact a qualified technician to inspect and reseat the PCB connector.
Common causes
- Defective connection of the connector between the indoor unit PCB and sub PCB
How to fix it
-
1
Contact a qualified technician to inspect and reseat the connector between the indoor unit PCB and sub PCB
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
C1 error — frequently asked questions
What does the C1 error mean on a Daikin air conditioner?
A communication fault was detected between the indoor unit PCB and sub PCB
What causes the C1 error?
The C1 error is usually caused by: Defective connection of the connector between the indoor unit PCB and sub PCB.
Can I fix the C1 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 C1 error?
Fixing the C1 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 C1 error?
We'd recommend addressing the C1 error before continuing to use the air conditioner, since hard-rated issues often involve a real fault rather than a minor glitch.