Blink count: 1
Red indicator flashes once repeatedly
Typical causes
- Indoor sensor signal abnormality
- Sensor connector contact issue
- Control-board input instability
Daikin Aircon Blinking Light Patterns
Use this Daikin blink table to match patterns and narrow next checks before booking.
Before you use this tool
This is a blink-pattern guidance table, not a model-exact diagnosis. Pattern meaning can vary by controller and series. If your controller shows a direct code (for example `CH21`, `U4`, `E6`), use the error-code guide for a faster match.
Safety warning
Stop using the unit and contact a technician if the breaker trips repeatedly, you smell burning, see sparks, hear loud electrical buzzing, or water is leaking from places it normally should not.
Daikin blink guide
Includes common SG residential blinking-light patterns with what they usually indicate and typical causes. Not every blink pattern maps to an error code.
Blink count: 2
Red indicator flashes two times repeatedly
Typical causes
- Outdoor control issue
- Inter-unit wiring fault
- Outdoor protection trip condition
Blink count: 3
Red indicator flashes three times repeatedly
Typical causes
- Compressor overload/protection event
- Inverter drive stress condition
- Refrigerant-side pressure abnormality
Blink count: Persistent or continuous
Indoor indicator blinks in a repeating fault pattern and diagnosis returns communication fault
Typical causes
- Loose indoor-outdoor interconnection wiring
- Terminal contact or wiring joint issue
- Indoor or outdoor PCB communication fault
Blink count: Persistent or continuous
Operation indicator blinks quickly during a defrost/protection cycle
Typical causes
- Outdoor coil defrost cycle
- Temporary protection control sequence
- Cold-weather operation transition
Blink count: Persistent or continuous
Operation indicator shows a slow green blink while the unit is in standby or startup sequence
Typical causes
- Unit is powered and preparing to run
- Control logic is waiting for load demand
- Model-specific normal indicator behavior
Blink count: Persistent or continuous
OPERATION lamp keeps blinking after a restart attempt
Typical causes
- Protection trip did not clear
- Sensor/control abnormality
- Indoor or outdoor control fault
Blink count: Persistent or continuous
Yellow/orange indicator blinks as maintenance or drainage warning
Typical causes
- Dirty or blocked filters
- Drainage blockage/water backup
- Model-specific maintenance reminder
Blink count: Not applicable
In diagnosis mode, cycling codes until a long beep confirms the matching fault code
Typical causes
- Unit has a stored fault condition
- User initiated fault-code check
- Code confirmation needed before service
Not sure how to read your Daikin blink pattern?
Send a short blink video and your model sticker. We'll advise the next step before any work is recommended.
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