HVACopediaFujitsu heat pump error codes
86 codes with causes and test steps, plus 1 settings tables.
| Code | Meaning | Severity |
|---|---|---|
| 3A | Indoor communication circuit (wired remote) error | Medium |
| 5U | Indoor unit error (general) | Medium |
| 6A | Display PCB micro communication error | Low |
| 9A | Expansion valve coil error | High |
| 9U | Outdoor unit error (general) | High |
| 11 | Serial communication error (indoor/outdoor) | High |
| 12 | Wired remote controller communication error | Medium |
| 14 | Network communication error | Medium |
| 15 | Check run unfinished / airflow auto-adjust error | Low |
| 16 | Peripheral unit / transmission PCB connection error | Medium |
| 18 | External communication error (WLAN / option adapter) | Low |
| 21 | Address / refrigerant circuit setting error | Medium |
| 22 | Indoor unit capacity error | Medium |
| 23 | Combination error | Medium |
| 24 | Connection unit number error | Medium |
| 26 | Indoor unit address setting error | Medium |
| 27 | Primary / secondary unit setup error | Medium |
| 29 | Connection unit number error (wired remote system) | Low |
| 31 | Power supply interruption error | Low |
| 32 | Indoor main PCB error (EEPROM / model info) | Medium |
| 33 | Indoor fan motor power consumption error | Medium |
| 35 | MANUAL AUTO button error | Low |
| 39 | Indoor fan motor power supply error | Medium |
| 41 | Room (intake air) temperature sensor error | Medium |
| 42 | Indoor coil (heat exchanger middle) sensor error | Medium |
| 44 | Human (occupancy) sensor error | Low |
| 51 | Indoor fan motor error | High |
| 52 | Indoor electronic expansion valve error | High |
| 53 | Drain pump error | Medium |
| 57 | Damper error | Low |
| 58 | Intake grille error | Low |
| 61 | Outdoor reverse / missing phase or wiring error | High |
| 62 | Outdoor main PCB error (EEPROM / model / micro comms) | High |
| 63 | Inverter error | High |
| 64 | PFC / active filter circuit error | High |
| 65 | IPM / trip terminal L error | High |
| 68 | Rush current limiting resistor temp rise error | Medium |
| 71 | Discharge temperature sensor error | Medium |
| 72 | Compressor temperature sensor error | Medium |
| 73 | Outdoor coil liquid temperature sensor error | Medium |
| 74 | Outdoor air temperature sensor error | Medium |
| 75 | Suction gas temperature sensor error | Medium |
| 76 | 2-way / 3-way valve temperature sensor error | Medium |
| 77 | Heat sink temperature sensor error | Medium |
| 82 | Sub-cool heat exchanger sensor error | Medium |
| 83 | Liquid pipe temperature sensor error | Medium |
| 84 | Current sensor error | High |
| 86 | Pressure sensor / high pressure switch error | High |
| 94 | Overcurrent trip detection | High |
| 95 | Compressor motor control / rotor position error | Critical |
| 97 | Outdoor fan motor error | High |
| 98 | Outdoor fan motor 2 error | High |
| 99 | 4-way valve error | High |
| A1 | High discharge temperature | High |
| A3 | High compressor temperature | High |
| A4 | High pressure error | High |
| A5 | Low pressure error | High |
| J1 | VRF branch box error | Medium |
| J2 | Branch box error (flexible multi) | Medium |
| Outdoor LED1 1 flash | Serial comms error, outdoor to indoor unit A (outdoor board LED) | High |
| Outdoor LED1 10 flashes | High pressure switch 2 error (outdoor board LED) | High |
| Outdoor LED1 11 flashes | Indoor unit capacity error (outdoor board LED) | Medium |
| Outdoor LED1 12 flashes | Overcurrent trip detection (outdoor board LED) | High |
| Outdoor LED1 13 flashes | Compressor rotor position detection error (outdoor board LED) | Critical |
| Outdoor LED1 14 flashes | Trip terminal L error (outdoor board LED) | High |
| Outdoor LED1 15 flashes | Outdoor fan motor error (outdoor board LED) | High |
| Outdoor LED1 17 flashes | Outdoor PCB micro communication error (outdoor board LED) | High |
| Outdoor LED1 18 flashes | High discharge temperature (outdoor board LED) | High |
| Outdoor LED1 19 flashes | High compressor temperature (outdoor board LED) | High |
| Outdoor LED1 2 flashes | Discharge temperature sensor error (outdoor board LED) | Medium |
| Outdoor LED1 20 flashes | 4-way valve error (outdoor board LED) | High |
| Outdoor LED1 21 flashes | Outdoor PCB model information error (outdoor board LED) | High |
| Outdoor LED1 22 flashes | Active filter / PFC circuit error (outdoor board LED) | High |
| Outdoor LED1 3 flashes | Outdoor coil middle temperature sensor error (outdoor board LED) | Medium |
| Outdoor LED1 4 flashes | Outdoor air temperature sensor error (outdoor board LED) | Medium |
| Outdoor LED1 5 flashes | 2-way valve sensor error, unit A (outdoor board LED) | Medium |
| Outdoor LED1 6 flashes | 3-way valve sensor error, unit A (outdoor board LED) | Medium |
| Outdoor LED1 7 flashes | Compressor temperature sensor error (outdoor board LED) | Medium |
| Outdoor LED1 8 flashes | Heat sink temperature sensor error (outdoor board LED) | Medium |
| Outdoor LED1 9 flashes | High pressure switch 1 error (outdoor board LED) | High |
| Outdoor LED2 1 flash | Serial comms error, outdoor to indoor unit B (outdoor board LED) | High |
| Outdoor LED2 5 flashes | 2-way valve sensor error, unit B (outdoor board LED) | Medium |
| Outdoor LED2 6 flashes | 3-way valve sensor error, unit B (outdoor board LED) | Medium |
| Outdoor LED3 1 flash | Serial comms error, outdoor to indoor unit C (24 type) (outdoor board LED) | High |
| Outdoor LED3 5 flashes | 2-way valve sensor error, unit C (24 type) (outdoor board LED) | Medium |
| Outdoor LED3 6 flashes | 3-way valve sensor error, unit C (24 type) (outdoor board LED) | Medium |
Settings and specs
Operating range and service space
Clearances · Fujitsu multi-zone outdoor 18/24 type
| Item | Value |
|---|---|
| Cooling outdoor range | 14 to 115 F DB |
| Heating outdoor range | 5 to 75 F DB |
| Cooling indoor range | 65 to 90 F DB |
| Heating indoor range | 60 to 88 F DB |
| Rear (open top, rear wall only) | 4 in. or more |
| Rear + sides | 4 in. rear, 10 in. sides |
| Front wall only | 24 in. or more |
| Between side-by-side units | 10 in. or more |
| Base height | 2 in. or more above floor |
- Unit tilt no more than 3 degrees and never toward the compressor side.
- Below 32 F outdoor do not fit the drain pipe/caps (freezing).
- Keep 40 in. from TV/radio equipment and wiring.
Source: Fujitsu Outdoor unit 18-24 type (North American trilingual) installation P-N 9374747160.pdf - sections 2.4.7 and 3.3
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.