Fujitsu AC Error Codes Guide – Meanings, Causes & Fixes

When your Fujitsu air conditioner shows an error code, it’s trying to tell you something’s not right — a sensor, communication line, power supply, or mechanical part has detected a fault. Knowing what the codes mean helps you fix small issues quickly and decide when it’s time for a technician.

How Error Codes Work in Fujitsu ACs

• Fujitsu units have built-in diagnostics. The indoor unit or remote control often displays codes like E:01, 11.2, or blinking sequences of LEDs.
• Some codes are stored in memory; others show in real time. You may have to press certain buttons (e.g. “CHECK”, “SELECT”, or “SET TEMP”) to view codes.
• Codes usually point to one of these categories: communication / wiring, sensor or thermistor faults, fan / motor / compressor or mechanical faults, overheat / pressure protections, indoor vs. outdoor unit mismatches or capacity issues, etc.

Complete List of Error Codes and What They Mean

Here are many of the Fujitsu error codes commonly used, what they typically indicate, and some things to check. This list draws on Fujitsu’s trouble-shooting PDFs and technical sources.

Code	What It Means / Description
E:00	Communication error: indoor unit ↔ remote control.
E:01	Communication error: indoor unit ↔ outdoor unit.
E:02	Room (indoor) temperature sensor open circuit.
E:03	Room temperature sensor short circuit.
E:04	Indoor heat exchanger / pipe sensor open.
E:05	Indoor heat exchanger / pipe sensor shorted.
E:06	Outdoor (or outdoor “exchanger”) pipe / heat exchanger sensor open.
E:07	Same sensor short circuit (outdoor exchanger) or similar.
E:08	Power source connection failure.
E:09	Float switch operated / water detection / drainage issue.
E:0A / 0A	Outdoor temperature sensor open.
E:0B	Outdoor temperature sensor short.
E:0C	Discharge pipe temperature sensor failure or open.
E:0D	Discharge pipe temp sensor short / failure.
E:0E	Outdoor high pressure / heatsink error.
E:0F	High discharge temperature (i.e. discharge sensor reading high).
11	Serial / comms error (indoor / outdoor units) in split / ducted systems.
12	Remote controller communication error.
18	External communication error (could be remote, branch, or other module).
1A	Compressor failure.
1B	Outdoor fan motor failure.
1C	Inverter to PCB communication error.
1D	Two-way (or multi-way) valve sensor failure.
1E	Expansion valve error.
1F	Connection ID Unit error (indoor likely).
22	Indoor unit capacity abnormal (e.g. mismatch vs outdoor unit, or config error).
24	Excessive high pressure protection is triggered in cooling mode.
25	PFC circuit error (Power Factor Correction / supply electronics).
26	Indoor unit address setting error (wired remote or multiple indoor units).
27	Indoor signal error.
28	Indoor heat exchanger temperature error.
29	Wired remote / connection unit number error.
3A	Indoor unit communication circuit (wired remote) error.
41	Indoor room-temperature thermistor / sensor failure.
42	Indoor heat exchange temp thermistor error.
51	Indoor fan motor error (often fan motor failure or blocked fan).
53	Indoor water drain abnormal (blocked, float switch, or overflow).
57	Indoor damper error.
58	Intake grille / louvre position error or grille stuck.
62	Outdoor unit main PCB error.
64	Outdoor unit Active Filter / PFC circuit error.
65	IPM error (inverter / power module) outdoors.
71	Outdoor discharge temperature thermistor error.
72	Outdoor compressor temperature thermistor error.
73	Outdoor heat exchange temperature thermistor error.
74	Outdoor air temperature thermistor error.
76	Outdoor operating valve thermistor error.
77	Outdoor unit heat sink temperature thermistor error.
86	Outdoor pressure sensor error.
94	Outdoor unit trip detection (protection mode).
95	Outdoor compressor motor control error.
97	Outdoor fan motor 1 error.
99	Outdoor 4-way valve error.
A1	Outdoor discharge temperature 1 error.
A3	Outdoor compressor temperature error.

What Triggers These Errors

Here are the common causes behind those codes:

• Sensor failures / thermistor issues: wires disconnected, sensor damaged, moisture ingress, corroded connection.
• Communication problems: indoor/outdoor units not talking properly, remote control errors, mis-wired multi-indoor systems.
• Mechanical faults: fan motor stuck or damaged, compressor not starting, valve actuator or damper/motor failures.
• Power issues / electronics: supply voltage too low or high, faulty PCBs, IPM (inverter module) malfunction, PFC circuits failing.
• Pressure / temperature extremes: excessively high discharge temperatures, overpressure in refrigerant circuits, heat sink issues, etc.
• Drainage / water issues: float switch triggered, blocked condensate line, water overflow.

Troubleshooting & Fixes You Can Try

Here are steps you can take to resolve many of these codes, assuming it’s safe for you to do so:

1. Power-cycle / Reset
   • Turn off unit via remote.
   • Switch off the breaker or isolator. Wait a few minutes.
   • Turn back on. Sometimes resets the system and clears transient errors.
2. Inspect Sensors & Wiring
   • Open panel (if safe) and look for loose connectors on sensors.
   • Check wiring between indoor & outdoor units.
   • Replace any damaged sensors/terminals.
3. Check Filters, Fans, and Airflow
   • Clean or replace air filters.
   • Remove debris around and inside outdoor unit.
   • Ensure fans spin freely (no obstruction).
4. Check Refrigerant Pressure / Discharge Conditions
   • If discharge temp is too high or pressure protection trips, ensure the condenser coil is clean.
   • Check refrigerant levels (this usually means calling in a licensed HVAC tech).
5. Check Remote and Communication Lines
   • Replace batteries in remote.
   • Ensure remote control is correctly paired.
   • For wired remote / multi-indoor systems, check address / signal wiring.
6. Inspect Control Boards / Electronics
   • Check for visible burning, corrosion, or component damage.
   • Ensure good power supply. If IPM or PCB components are damaged, those usually need professional repair/replacement.
7. Drainage / Water-Related Checks
   • Ensure condensate drains are clear.
   • Check float switch functionality.
   • Ascertain the drain pan isn’t overflowing or cracked.

When to Call a Technician

Some errors are too dangerous or complex to fix as a DIY job. You should call a qualified Fujitsu / HVAC technician in cases like:

• Compressor failure codes (e.g. 1A) or major mechanical failures.
• High pressure / discharge temperature protection repeatedly triggering.
• Electronic board failures (IPM, PCB) or PFC circuit faults.
• Refrigerant leaks or pressure repairs (licensed handling required).
• Warranty or safety-covering issues (so you don’t void warranty).

Tips for Preventing Fujitsu AC Errors

• Regular maintenance (filter cleaning, coil cleaning, keeping outdoor unit free from leaves/obstructions).
• Keep sensors and their housings clean, dry, and protected from elements.
• Ensure correct installation (correct pipe routing, wiring, remote addressing).
• Ensure stable electrical supply; use surge protection where practical.
• Have seasonal checkups before hot or cold weather peaks.

Conclusion

Fujitsu AC error codes are powerful tools to help diagnose problems before they become big, expensive repairs. With this full guide, you can understand what each code usually means, try simple fixes where safe to do so, and know when to call in professional help.

If you tell me your exact Fujitsu AC model (e.g. model number from the indoor unit), I can pull up its specific error code list so troubleshooting is even more accurate.