Icon
Reliable Heating and Cooling Solutions – Quality Service, Fair Prices, Guaranteed Satisfaction!

Follow Us On:

Logo
Contact US!

Fujitsu Heat Pump Error Codes

Updated · by Aurora Star Tech Inc.

86 Fujitsu Heat Pump error codes and diagnostic codes, with causes and troubleshooting steps for each. Select a code, or find your model below.

Homeowner with a heat pump problem? Call (647) 657-2977 or book a service call — licensed technicians across Vaughan and the GTA.

Fujitsu Heat Pump error codes list

CodeMeaningSeverity
3AIndoor communication circuit (wired remote) errorMedium
5UIndoor unit error (general)Medium
6ADisplay PCB micro communication errorLow
9AExpansion valve coil errorHigh
9UOutdoor unit error (general)High
11Serial communication error (indoor/outdoor)High
12Wired remote controller communication errorMedium
14Network communication errorMedium
15Check run unfinished / airflow auto-adjust errorLow
16Peripheral unit / transmission PCB connection errorMedium
18External communication error (WLAN / option adapter)Low
21Address / refrigerant circuit setting errorMedium
22Indoor unit capacity errorMedium
23Combination errorMedium
24Connection unit number errorMedium
26Indoor unit address setting errorMedium
27Primary / secondary unit setup errorMedium
29Connection unit number error (wired remote system)Low
31Power supply interruption errorLow
32Indoor main PCB error (EEPROM / model info)Medium
33Indoor fan motor power consumption errorMedium
35MANUAL AUTO button errorLow
39Indoor fan motor power supply errorMedium
41Room (intake air) temperature sensor errorMedium
42Indoor coil (heat exchanger middle) sensor errorMedium
44Human (occupancy) sensor errorLow
51Indoor fan motor errorHigh
52Indoor electronic expansion valve errorHigh
53Drain pump errorMedium
57Damper errorLow
58Intake grille errorLow
61Outdoor reverse / missing phase or wiring errorHigh
62Outdoor main PCB error (EEPROM / model / micro comms)High
63Inverter errorHigh
64PFC / active filter circuit errorHigh
65IPM / trip terminal L errorHigh
68Rush current limiting resistor temp rise errorMedium
71Discharge temperature sensor errorMedium
72Compressor temperature sensor errorMedium
73Outdoor coil liquid temperature sensor errorMedium
74Outdoor air temperature sensor errorMedium
75Suction gas temperature sensor errorMedium
762-way / 3-way valve temperature sensor errorMedium
77Heat sink temperature sensor errorMedium
82Sub-cool heat exchanger sensor errorMedium
83Liquid pipe temperature sensor errorMedium
84Current sensor errorHigh
86Pressure sensor / high pressure switch errorHigh
94Overcurrent trip detectionHigh
95Compressor motor control / rotor position errorCritical
97Outdoor fan motor errorHigh
98Outdoor fan motor 2 errorHigh
994-way valve errorHigh
A1High discharge temperatureHigh
A3High compressor temperatureHigh
A4High pressure errorHigh
A5Low pressure errorHigh
J1VRF branch box errorMedium
J2Branch box error (flexible multi)Medium
Outdoor LED1 1 flashSerial comms error, outdoor to indoor unit A (outdoor board LED)High
Outdoor LED1 2 flashesDischarge temperature sensor error (outdoor board LED)Medium
Outdoor LED1 3 flashesOutdoor coil middle temperature sensor error (outdoor board LED)Medium
Outdoor LED1 4 flashesOutdoor air temperature sensor error (outdoor board LED)Medium
Outdoor LED1 5 flashes2-way valve sensor error, unit A (outdoor board LED)Medium
Outdoor LED1 6 flashes3-way valve sensor error, unit A (outdoor board LED)Medium
Outdoor LED1 7 flashesCompressor temperature sensor error (outdoor board LED)Medium
Outdoor LED1 8 flashesHeat sink temperature sensor error (outdoor board LED)Medium
Outdoor LED1 9 flashesHigh pressure switch 1 error (outdoor board LED)High
Outdoor LED1 10 flashesHigh pressure switch 2 error (outdoor board LED)High
Outdoor LED1 11 flashesIndoor unit capacity error (outdoor board LED)Medium
Outdoor LED1 12 flashesOvercurrent trip detection (outdoor board LED)High
Outdoor LED1 13 flashesCompressor rotor position detection error (outdoor board LED)Critical
Outdoor LED1 14 flashesTrip terminal L error (outdoor board LED)High
Outdoor LED1 15 flashesOutdoor fan motor error (outdoor board LED)High
Outdoor LED1 17 flashesOutdoor PCB micro communication error (outdoor board LED)High
Outdoor LED1 18 flashesHigh discharge temperature (outdoor board LED)High
Outdoor LED1 19 flashesHigh compressor temperature (outdoor board LED)High
Outdoor LED1 20 flashes4-way valve error (outdoor board LED)High
Outdoor LED1 21 flashesOutdoor PCB model information error (outdoor board LED)High
Outdoor LED1 22 flashesActive filter / PFC circuit error (outdoor board LED)High
Outdoor LED2 1 flashSerial comms error, outdoor to indoor unit B (outdoor board LED)High
Outdoor LED2 5 flashes2-way valve sensor error, unit B (outdoor board LED)Medium
Outdoor LED2 6 flashes3-way valve sensor error, unit B (outdoor board LED)Medium
Outdoor LED3 1 flashSerial comms error, outdoor to indoor unit C (24 type) (outdoor board LED)High
Outdoor LED3 5 flashes2-way valve sensor error, unit C (24 type) (outdoor board LED)Medium
Outdoor LED3 6 flashes3-way valve sensor error, unit C (24 type) (outdoor board LED)Medium

Fujitsu Heat Pump specs and setup data

Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

© 2026 Aurora Star Tech Inc. All rights reserved. This page may not be copied, republished or used to train other systems without written permission.

Emergency HVAC Service

647-657-2977