Daikin Mini Split Error Code U8: How to Fix It

Medium 30-90 minutes Medium Severity Verified June 2026
Summarize with ChatGPTSummarize with ClaudeSummarize with Perplexity Add as Preferred Source on Google
Error Code
U8
Brand
Daikin
Product Type
mini_split
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
30-90 minutes
Error code U8 on your Daikin mini split indicates a transmission error between the main and sub remote controllers. This typically means the indoor units are not communicating properly with each other or with the outdoor unit.
Ad

Tools You'll Need

How to Fix Error Code U8

  1. Turn Off the System and Disconnect Power

    Always disconnect power before working on the unit to avoid electric shock.

  2. Check Wiring Connections

    Do not touch any live parts. Ensure power is off.

  3. Check for Shorted or Open Wires

  4. Reset the System

  5. Inspect the Main PCB

    PCB replacement should be performed by a qualified technician.

  6. Replace the Communication Board or Main PCB

    Ensure the replacement part is compatible with your model.

Parts You May Need

Main PCB (Printed Circuit Board)
Check Price on Amazon
Communication Cable
Check Price on Amazon
Main PCB (Printed Circuit Board)
Check Price on Amazon
Communication Cable
Check Price on Amazon
Main PCB (Printed Circuit Board)
Check Price on Amazon
Communication Cable
Check Price on Amazon
Main PCB (Printed Circuit Board)
Check Price on Amazon
Communication Cable
Check Price on Amazon
Ad

When to Call a Professional

If you are not comfortable working with electrical wiring, or if the error persists after checking wiring and resetting the system, call a qualified HVAC technician. PCB replacement should only be done by a professional.

Frequently Asked Questions

What does error code U8 mean on a Daikin mini split?
Error code U8 indicates a transmission abnormal error between the main and sub remote controllers. It usually means the indoor units are not communicating properly with each other or with the outdoor unit.
Can I fix Daikin error code U8 myself?
Yes, you can try basic troubleshooting like resetting the system and checking wiring connections. If the problem is with the PCB, you may need professional help.
How do I reset a Daikin mini split after error U8?
Turn off the unit and disconnect power for 5 minutes. Then turn it back on and press the Cancel button on the remote to clear the error. If it persists, check wiring.
What causes transmission error U8 on Daikin systems?
Common causes include loose or damaged wiring between indoor and outdoor units, a faulty communication board, or a defective main PCB.
How much does it cost to fix error code U8?
If it's a simple wiring fix, it may cost $100-$200 for a service call. PCB replacement can cost $300-$800 including parts and labor.

Related Error Codes