Fujitsu Aircon Blinking Light: What It Means and What to Do
Fujitsu units report faults through the operation and timer lamps, and the count on each lamp points to a stored code. The economy lamp confirms that an error is active, while a wired remote spells out the same entry in text.
By Team Snowflake | Updated 15 Sept 2026
How the lamps on a Fujitsu indoor unit are arranged
Fujitsu wall-mounted units use three panel lamps, and the colour set changes between generations. Newer ASAG and ASTG models run a green operation lamp and an orange timer lamp. Older units may swap those colours. Count the pattern rather than trusting the shade.
Ceiling cassettes move those lamps out of sight, onto a board above the room. A wired remote is the only practical way to read them.
| Lamp | Colour | Role by unit type |
|---|---|---|
| Operation lamp | Green or red, by model | Wall panel on most models. Running state, and the first half of a blink code |
| Timer lamp | Orange or green, by model | Wall panel on most models. Timer state, and the second half of a blink code |
| Economy lamp | Green | Wall panel only. Energy-saving mode, and the active-error signal |
- Lamp
- Operation lamp
- Colour
- Green or red, by model
- Role by unit type
- Wall panel on most models. Running state, and the first half of a blink code
- Lamp
- Timer lamp
- Colour
- Orange or green, by model
- Role by unit type
- Wall panel on most models. Timer state, and the second half of a blink code
- Lamp
- Economy lamp
- Colour
- Green
- Role by unit type
- Wall panel only. Energy-saving mode, and the active-error signal
Lamp behaviour that is normal
Before counting anything, rule out the patterns that belong to normal operation. They are mistaken for faults often enough to matter. A lamp that holds steady through a cooling cycle is doing its job.
A short rapid sequence on the operation lamp, with the economy lamp dark, belongs to defrost or a start check. It resolves within minutes and needs no action from you.
| Pattern | What it means |
|---|---|
| Steady operation lamp | Unit running in cooling or dry mode |
| Slow operation blink | Standby, or a start delayed by the timer |
| Airflow held back after start | Delay before the compressor restarts |
| Steady timer lamp | Timer function active |
| Steady economy lamp | Energy-saving mode running at reduced output |
- Pattern
- Steady operation lamp
- What it means
- Unit running in cooling or dry mode
- Pattern
- Slow operation blink
- What it means
- Standby, or a start delayed by the timer
- Pattern
- Airflow held back after start
- What it means
- Delay before the compressor restarts
- Pattern
- Steady timer lamp
- What it means
- Timer function active
- Pattern
- Steady economy lamp
- What it means
- Energy-saving mode running at reduced output
Fault patterns and the Fujitsu codes they map to
When a Fujitsu fault is active, the economy lamp flashes and the other two lamps count out the code. The patterns below match the model tables, and each one resolves to a stored code in the Fujitsu registry.
A wired remote reports the same conditions in text form, from E:00 for a remote communication failure to E:18 for a current transformer error. The text form and the blink form describe the same stored condition. Search the exact entry in the Fujitsu error code list before work is approved.
| Pattern | Code | What the code covers |
|---|---|---|
| Economy lamp flashing, operation 1, timer 1 | OP 1x / TIMER 1x | Serial communication error |
| Operation dark, timer 2 | OP off / TIMER 2x | Reverse communication failure at startup |
| Operation 2, timer 2 | OP 2x / TIMER 2x | Indoor capacity, air sensor, or board error |
| Operation 2, timer 6 | OP 2x / TIMER 6x | Address setting error, or float switch operation |
| Operation 3, timer 5 | OP 3x / TIMER 5x | Manual auto switch error |
| Operation 4, timer 1 | OP 4x / TIMER 1x | Room temperature sensor error |
| Operation 5, timer 1 | OP 5x / TIMER 1x | Indoor fan motor error |
| Operation 5, timer 3 | OP 5x / TIMER 3x | Drain pump error |
| Operation 7, timer 3 | OP 7x / TIMER 3x | Outdoor heat exchanger liquid sensor error |
| Operation 8, timer 4 | OP 8x / TIMER 4x | Current sensor or PFC circuit error |
- Pattern
- Economy lamp flashing, operation 1, timer 1
- Code
- OP 1x / TIMER 1x
- What the code covers
- Serial communication error
- Pattern
- Operation dark, timer 2
- Code
- OP off / TIMER 2x
- What the code covers
- Reverse communication failure at startup
- Pattern
- Operation 2, timer 2
- Code
- OP 2x / TIMER 2x
- What the code covers
- Indoor capacity, air sensor, or board error
- Pattern
- Operation 2, timer 6
- Code
- OP 2x / TIMER 6x
- What the code covers
- Address setting error, or float switch operation
- Pattern
- Operation 3, timer 5
- Code
- OP 3x / TIMER 5x
- What the code covers
- Manual auto switch error
- Pattern
- Operation 4, timer 1
- Code
- OP 4x / TIMER 1x
- What the code covers
- Room temperature sensor error
- Pattern
- Operation 5, timer 1
- Code
- OP 5x / TIMER 1x
- What the code covers
- Indoor fan motor error
- Pattern
- Operation 5, timer 3
- Code
- OP 5x / TIMER 3x
- What the code covers
- Drain pump error
- Pattern
- Operation 7, timer 3
- Code
- OP 7x / TIMER 3x
- What the code covers
- Outdoor heat exchanger liquid sensor error
- Pattern
- Operation 8, timer 4
- Code
- OP 8x / TIMER 4x
- What the code covers
- Current sensor or PFC circuit error
Reading the code from the Fujitsu remote
Fujitsu wired remotes show the current code on the screen directly. When a code is held in memory, press the Energy Save and Zone Control buttons together for three seconds to bring it up. The stored entry survives while the unit is off, so an earlier fault can still be read.
On LED-only units, count each lamp through at least two full repetitions before writing anything down. Order matters: the first figure comes from the operation lamp, and the second comes from the timer lamp.
In a multi-split home, run the check at every indoor unit. A single outdoor unit can leave one room with a code while the rest look normal.
Faults on a Fujitsu multi-split system
A Fujitsu multi-split shares one communication line and one refrigerant circuit across the connected heads, so an outdoor fault can light every indoor unit at once. The pattern then repeats at each panel.
When a single head blinks while the others cool normally, the trouble sits at that unit, its sensor, or its wiring. Note the operation and timer counts from each room separately for the technician.
Record the counts from each room before calling anyone. A technician can match the pattern to the circuit without repeating the walk-through.
Common questions
What does the blinking light on a Fujitsu aircon mean?
Which Fujitsu light patterns are normal?
How do I read a stored Fujitsu code?
Does a Fujitsu multi-split show the same fault in every room?
What should I have ready when booking a Fujitsu diagnosis?
Sources
- Fujitsu ASYG LMCE Installation Manual Error Codes
Fujitsu General · Checked
ASYG LMCE indoor lamp signals and blink-pair fault codes.
- Fujitsu ASYG KPCE Installation Manual Error Codes
Fujitsu General · Checked
ASYG KPCE lamp-blink rows and matching wired-remote numeric codes.
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Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.