SplitAtlas

Error-code hub

Fujitsu error codes

Fujitsu AIRSTAGE systems report faults as a two-part code, and on wall units the indoor LEDs flash a counted pattern that maps to it - the operation and timer lamps blink a specific number of times each. The 28 codes below cover the Altair and Orion series. Fujitsu's service documentation is unusually thorough, and where it gives a homeowner-safe check we have included it.

See Fujitsumini-splits ->Common FirstStatus DisplaysError Codes
Status displays
8
Error codes
28

Unit applicability

Match your unit before reading the table

This table is sourced for AIRSTAGE H-series. If your unit is a different generation or product line not named here, the same display code may vary by generation.

AIRSTAGE H-series43 models

Common codes first

Most broadly applicable documented codes

Ranking basis: we do not have failure-frequency telemetry. These are ordered by breadth of affected systems in the SplitAtlas catalog - the documented product line's published model count, whether the same code appears on more than one product line, and any manual applicability notes we hold. This is a breadth ranking, not a popularity claim.

5U.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 5U.1 means the outdoor unit is reporting an indoor-unit fault. The outdoor display points you back to the affected indoor unit instead of naming one outdoor component.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Turn the system off once and check only user-safe items: clean filters, confirm the remote is set normally, and look for visible water at the indoor head. If the code returns, stop.
View the fix
11.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 11.3 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
View the fix
11.4

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 11.4 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
View the fix
16.5

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 16.5 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
View the fix
22.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 22.1 means the outdoor unit sees an indoor-unit match or connection pattern it is not allowed to run.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Do not change wiring, DIP switches, or indoor-unit combinations. Reset once only if the system previously ran normally; if the code returns, leave it for the installer.
View the fix
23.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 23.1 means the outdoor unit sees an indoor-unit match or connection pattern it is not allowed to run.

AdvisoryTechnician
Breadth evidence
43 published catalog models on its documented product line. Manual applicability notes: Fujitsu Halcyon/AIRSTAGE R-32 AOUH18KWAS2, AOUH24KWAS3, AOUH36KWAS4, and AOUH45KWAS5 outdoor-unit manuals where Section 14-3 lists the same SW1/MONITOR error-code table.; Fujitsu AOUH18KWAH2 and AOUH36KWAH4 XLTH sibling design manuals where the extracted Section 14-3 table matches the KWAS manuals.
Safe first check
Do not change wiring, DIP switches, or indoor-unit combinations. Reset once only if the system previously ran normally; if the code returns, leave it for the installer.
View the fix

Safe first checks

Checks you can do without opening the unit

These codes have homeowner-safe steps such as filters, airflow, condensate/drain checks, remote/controller items, or a single safe power reset. If the code returns, stop at the boundary in the card.

5U.1Technician

Turn the system off once and check only user-safe items: clean filters, confirm the remote is set normally, and look for visible water at the indoor head. If the code returns, stop.

Read the full code guide
11.3Technician

Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.

Read the full code guide
11.4Technician

Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.

Read the full code guide
16.5Technician

Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.

Read the full code guide

Fujitsu mini-splits

Use the Fujitsu catalog to connect these manual error codes to current model pages and replacement options.

See Fujitsumini-splits ->

Status displays

CHECK RUN

Check run is a setup/service mode used to verify indoor-unit wiring and piping order. Flashing MONITOR LEDs during this mode are progress/result indications, not fault codes by themselves.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
If a technician started check run, let them finish. If the system seems stuck in check run, turn it off once and call the installing contractor.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

CHECK RUN RESULTS

After check run, the MONITOR LEDs light in sequence to show whether the connected indoor units match the expected order. This is a setup result display, not a component failure code.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Do not change wiring or DIP switches. If the result shows a mismatch or appears after installation, have the installer correct it.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

DEFROST DURING CHECK RUN

During check-run result display, the manual says automatic defrost may operate if frost is on the outdoor unit. That is a normal protective operation, not an error by itself.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Let defrost finish. Keep snow and loose debris away from the outdoor unit base, but do not chip ice from the coil.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

POWER/MODE ON

A steady green POWER/MODE LED means the outdoor board is powered, including while an error may also be present. It is not an error code by itself.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
No repair action is needed for a steady POWER/MODE LED if the system is operating normally. Look for the red ERROR LED or a stored SW1 code only if comfort is poor.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

PUMP DOWN

Pump down is a service procedure for moving or discarding the unit. A POWER/MODE three-blink indication during pump down is not a homeowner repair code.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Do not start pump down yourself. If it appears unexpectedly, stop operation once and call a licensed HVAC technician.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

PUMP DOWN AUTO STOP

If pump down is not stopped manually, the manual says operation stops automatically after 15 minutes and the LEDs show the pump-down stop indication. That timeout is not a normal comfort-mode error code.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Leave the system off and do not open service valves or refrigerant fittings. Have a licensed technician verify the pump-down state before using the unit.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

SW1 CODE DISPLAY

When the red ERROR LED is blinking, briefly pressing SW1 makes the MONITOR LEDs blink out the dot-decimal diagnostic code. The display method is not a separate failure.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Record the exact dot-decimal code and which indoor position LED is lit, if visible. Do not remove covers or probe wiring to read more.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

TEST RUN

Test run starts from SW1 after the outdoor unit is prepared for COOL or HEAT test operation. A POWER/MODE one-blink indication during test run is not a fault code.

Not an error
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
If a technician started test run, let them finish. If it appears during normal use, stop the system once and call for service if normal controls do not return.
Status note
This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.
View the fix ->

All error codes

11.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 11.3 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one safe reset, appeared after installation/service, or more than one indoor unit is affected. Tell them the exact Fujitsu SW1 code is 11.3 and the Section 14-3 meaning is: Serial communication error (outdoor).
View the fix ->

11.4

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 11.4 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one safe reset, appeared after installation/service, or more than one indoor unit is affected. Tell them the exact Fujitsu SW1 code is 11.4 and the Section 14-3 meaning is: Serial communication error during operation.
View the fix ->

16.5

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 16.5 means the indoor/controller communication path to the outdoor unit is not exchanging data normally.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one safe reset, appeared after installation/service, or more than one indoor unit is affected. Tell them the exact Fujitsu SW1 code is 16.5 and the Section 14-3 meaning is: Communication error between controller and outdoor unit.
View the fix ->

22.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 22.1 means the outdoor unit sees an indoor-unit match or connection pattern it is not allowed to run.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Do not change wiring, DIP switches, or indoor-unit combinations. Reset once only if the system previously ran normally; if the code returns, leave it for the installer.
When to call a pro
Call the installing contractor or a licensed HVAC technician if this code appears. Tell them the exact Fujitsu SW1 code is 22.1 and the Section 14-3 meaning is: Indoor unit capacity error.
View the fix ->

23.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 23.1 means the outdoor unit sees an indoor-unit match or connection pattern it is not allowed to run.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Do not change wiring, DIP switches, or indoor-unit combinations. Reset once only if the system previously ran normally; if the code returns, leave it for the installer.
When to call a pro
Call the installing contractor or a licensed HVAC technician if this code appears. Tell them the exact Fujitsu SW1 code is 23.1 and the Section 14-3 meaning is: Connection prohibited (series error).
View the fix ->

5U.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 5U.1 means the outdoor unit is reporting an indoor-unit fault. The outdoor display points you back to the affected indoor unit instead of naming one outdoor component.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off once and check only user-safe items: clean filters, confirm the remote is set normally, and look for visible water at the indoor head. If the code returns, stop.
When to call a pro
Call a licensed HVAC technician if the indoor unit still will not run, water is present, or the code returns. Tell them the exact Fujitsu SW1 code is 5U.1 and the Section 14-3 meaning is: Indoor unit error.
View the fix ->

62.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 62.1 means the outdoor control-board memory/model data did not pass the outdoor unit's internal check.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset or appeared after board/service work. Tell them the exact Fujitsu SW1 code is 62.1 and the Section 14-3 meaning is: PCB model information error.
View the fix ->

62.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 62.3 means the outdoor control-board memory/model data did not pass the outdoor unit's internal check.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset or appeared after board/service work. Tell them the exact Fujitsu SW1 code is 62.3 and the Section 14-3 meaning is: EEPROM access error.
View the fix ->

62.8

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 62.8 means the outdoor control-board memory/model data did not pass the outdoor unit's internal check.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset or appeared after board/service work. Tell them the exact Fujitsu SW1 code is 62.8 and the Section 14-3 meaning is: EEPROM data corruption error.
View the fix ->

63.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 63.1 means the outdoor inverter/IPM electronics did not pass the outdoor unit's internal check.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset or appeared after board/service work. Tell them the exact Fujitsu SW1 code is 63.1 and the Section 14-3 meaning is: Inverter error.
View the fix ->

65.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 65.3 means the outdoor inverter/IPM electronics did not pass the outdoor unit's internal check.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset or appeared after board/service work. Tell them the exact Fujitsu SW1 code is 65.3 and the Section 14-3 meaning is: IPM error (trip terminal L).
View the fix ->

71.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 71.1 means the outdoor unit cannot trust the discharge temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 71.1 and the Section 14-3 meaning is: Discharge temp sensor error.
View the fix ->

72.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 72.1 means the outdoor unit cannot trust the compressor temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 72.1 and the Section 14-3 meaning is: Compressor temp sensor error.
View the fix ->

73.2

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 73.2 means the outdoor unit cannot trust the heat exchanger middle temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 73.2 and the Section 14-3 meaning is: Heat exchanger middle temp sensor error.
View the fix ->

73.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 73.3 means the outdoor unit cannot trust the heat exchanger liquid temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 73.3 and the Section 14-3 meaning is: Heat exchanger liquid temp sensor error.
View the fix ->

74.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 74.1 means the outdoor unit cannot trust the outdoor temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 74.1 and the Section 14-3 meaning is: Outdoor temp sensor error.
View the fix ->

75.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 75.1 means the outdoor unit cannot trust the suction gas temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 75.1 and the Section 14-3 meaning is: Suction gas temp sensor error.
View the fix ->

76.2

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 76.2 means the outdoor unit cannot trust the valve sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 76.2 and the Section 14-3 meaning is: Valve sensor error.
View the fix ->

84.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 84.1 means the outdoor unit cannot trust the heat sink temperature sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 84.1 and the Section 14-3 meaning is: Heat sink temp sensor error.
View the fix ->

86.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 86.1 means the outdoor unit cannot trust the current sensor 1 reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 86.1 and the Section 14-3 meaning is: Current sensor 1 error.
View the fix ->

97.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 97.3 means the outdoor unit is not controlling the compressor motor normally. Repeated resets can stress the compressor and inverter.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off and reset once if safe. If the code returns, leave the system off and do not force repeated compressor starts.
When to call a pro
Call a licensed HVAC technician if the code returns or the outdoor unit will not start. Tell them the exact Fujitsu SW1 code is 97.3 and the Section 14-3 meaning is: Compressor motor control error.
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98.3

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 98.3 means the outdoor unit is not seeing the expected duty/feedback from one outdoor fan motor.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off and look only through the grille for obvious loose debris, snow, or ice. Clear loose debris outside the cabinet, reset once, and stop if the code returns.
When to call a pro
Call a licensed HVAC technician if the fan blade is damaged, the fan is not visibly blocked, or the code returns. Tell them the exact Fujitsu SW1 code is 98.3 and the Section 14-3 meaning is: Fan motor 1 error.
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99.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 99.1 means the outdoor unit is not seeing the expected duty/feedback from one outdoor fan motor.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off and look only through the grille for obvious loose debris, snow, or ice. Clear loose debris outside the cabinet, reset once, and stop if the code returns.
When to call a pro
Call a licensed HVAC technician if the fan blade is damaged, the fan is not visibly blocked, or the code returns. Tell them the exact Fujitsu SW1 code is 99.1 and the Section 14-3 meaning is: Fan motor 2 error.
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A1.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code A1.1 means the outdoor unit detected a problem with expansion valve coil 1. The valve controls refrigerant flow and is not homeowner-serviceable.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off and reset once if safe. Do not open service valves, connect gauges, add refrigerant, or remove outdoor panels.
When to call a pro
Call a licensed HVAC technician if the code appears or returns after one reset. Tell them the exact Fujitsu SW1 code is A1.1 and the Section 14-3 meaning is: Coil 1 (expansion valve 1) error.
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A3.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code A3.1 means Discharge temperature 1 error. The outdoor unit is protecting itself until a technician confirms the cause.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service.
When to call a pro
Call a licensed HVAC technician if the code returns after one reset. Tell them the exact Fujitsu SW1 code is A3.1 and the Section 14-3 meaning is: Discharge temperature 1 error.
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86.4

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 86.4 means the outdoor unit cannot trust the discharge pressure sensor reading. That reading protects compressor, inverter, pressure, or refrigerant-flow control.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off with the remote, then power cycle once at the breaker or disconnect only if you can do that safely. Expected result: a temporary control lockup clears; if the same code returns, stop resetting and schedule service. Do not remove outdoor panels or unplug sensors.
When to call a pro
Call a licensed HVAC technician if the code returns after the safe reset. Tell them the exact Fujitsu SW1 code is 86.4 and the Section 14-3 meaning is: Discharge pressure sensor error.
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94.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 94.1 means the outdoor unit detected an abnormal high-pressure or pressure-sensor condition and is protecting the refrigeration circuit.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off, clean indoor filters, and clear leaves, snow, or debris around the outdoor unit without removing panels. Reset once. If the code returns, leave it off.
When to call a pro
Call a licensed HVAC technician if the code returns, if airflow is already clear, or if the outdoor unit sounds abnormal. Tell them the exact Fujitsu SW1 code is 94.1 and the Section 14-3 meaning is: High pressure switch 1 error.
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95.1

Fujitsu's outdoor board shows these dot-decimal codes only after an error is active: the red ERROR LED blinks at high speed, then a brief SW1 press makes the MONITOR LEDs blink out the code. Code 95.1 means the outdoor unit detected a protective trip. The code does not name a homeowner-serviceable part.

AdvisoryTechnician
Sourced Jul 2026
Applies to
AIRSTAGE H-series
Homeowner fix
Turn the system off, clean filters, and clear the outdoor unit perimeter without removing panels. Reset once only; if the trip returns, leave the system off.
When to call a pro
Call a licensed HVAC technician if the trip returns after one reset or if a breaker trips. Tell them the exact Fujitsu SW1 code is 95.1 and the Section 14-3 meaning is: Trip detection.
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