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Fujitsu Air Conditioner 11 Error Code
Indoor and outdoor units can't communicate. Here is what it means and how to clear it, easiest fix first.
The indoor and outdoor units aren't exchanging signals. A power interruption, the outdoor unit having no power, loose or damaged connecting wiring, or a board fault in either unit are the usual causes.
Lamp pattern: on models that show faults with the indicator lamps, Fujitsu's tables for many current wall-mounted (RL/RLS/RLX, LZAH), compact ducted (RGLX) and RLF multi-zone units show this code as the Operation lamp flashing 1 time and the Timer lamp flashing 1 time, with the Economy lamp marked "continuous". Other Fujitsu units, such as universal-mount and ceiling-suspended models, use different lamps. A wired controller shows the code as a number. Fujitsu's FGLair app table lists sub-codes 11.1 to 11.4, and service manuals write it as E: 11. On the older code set this fault used 01 or 13, and an old-style 11 means a model or memory (EEPROM) mismatch instead. Fujitsu's older code set (for example older 9CQ/9RLQ/12CQ wall units, RMLQ-series multi-zone heads and some RCLX ceiling cassettes) uses different numbers for many faults, so always check the manual for your model.
How to fix Fujitsu 11
Reset the power at the breaker
Switch the system off with the remote, then turn off its circuit breaker in your home's main panel. Wait about 5 minutes, switch the breaker back on and restart the unit. If the code appeared after a storm or power cut, restarting both units together sometimes clears it.
Check the outdoor unit's breaker
Many systems have a separate breaker for the outdoor unit. Make sure it is on. If it trips again right away, leave it off and call for service.
When to call a technician
If the code returns, a technician needs to check the wiring and voltage between the units and the boards. Don't open the terminal covers or the outdoor unit's electrical panel.
Parts that commonly cause 11
- indoor/outdoor connecting cable
- indoor control board
- outdoor control board
Order parts by your exact model number so they fit.
Other Fujitsu air conditioner codes
- 12Wired remote controller communication error
- 18External or Wi-Fi adapter communication error
- 32Indoor unit control board error
- 35MANUAL AUTO button stuck
- 41Room temperature sensor error
- 42Indoor coil temperature sensor error
- 51Indoor fan motor error
- 53Drain pump error
- 62Outdoor unit main board error
- 63Inverter error
- 65IPM (power module) protection
- 71-74Outdoor unit temperature sensor error
- 94Compressor overcurrent (trip detection)
- 95Compressor motor control error
- 97Outdoor fan motor error
- 99Reversing (4-way) valve error
- A1Discharge temperature too high
- A3Compressor temperature too high
- A5Low pressure error
Frequently asked questions
What does 11 mean on a Fujitsu air conditioner?
The indoor and outdoor units aren't exchanging signals. A power interruption, the outdoor unit having no power, loose or damaged connecting wiring, or a board fault in either unit are the usual causes.
Can I fix Fujitsu 11 myself?
Only the basic checks. You can safely try the steps above, but 11 usually points to a part or fault that needs a technician.
What if 11 keeps coming back?
A code that returns after a reset and the checks above usually means a part is wearing out. Note when 11 appears (which cycle, how often) and have your model number ready; it helps a technician bring the right part on the first visit.
Last reviewed 2026-10-19. Codes and steps can vary by model; check your owner's manual.