HVACopediaFujitsu · Heat pump
5U Indoor unit error (general)
What the control is telling you
A general indoor fault code; the detailed cause is one of the indoor errors (11, 12, 18, 22, 23, 32, 35, 41, 42, 51). Indoor lamps: OPERATION (green) flashes 5x, TIMER (orange) flashes 15x, ECONOMY (green) flashes fast nonstop; wired remote shows 5U.
Applies to: Fujitsu ductless heat pumps: Fujitsu ductless split/multi/VRF (general code list), Fujitsu wall-mounted 7-15 (NA ASU/AOU type), Fujitsu slim duct ARU 7-18 (LL type)
Likely causes
- See the specific indoor error
Test and repair steps
- Read the detailed code on a wired remote or the mobile app (it gives a sub-code such as 41.1).
- Then follow the steps for that specific code.
Settings for these units
- Operating range and service space · Fujitsu multi-zone outdoor 18/24 type
Other codes on the same units
- 3A Indoor communication circuit (wired remote) error
- 6A Display PCB micro communication error
- 9A Expansion valve coil error
- 9U Outdoor unit error (general)
- 11 Serial communication error (indoor/outdoor)
- 12 Wired remote controller communication error
- 14 Network communication error
- 15 Check run unfinished / airflow auto-adjust error
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Source: Fujitsu All Fujitsu split - multi - VRF (generic code list) codes.pdf - section error code table (indoor LED flashes); Fujitsu Wall-mounted 7-9-12-15 (North American trilingual, UTY-RNNUM remotes; e.g. ASU9-12-15 RLF1-RLS familie.pdf - section 14 Error codes; Fujitsu Wall-mounted KMCG (ASEH-AOEH 07-14) - Fujitsu UK; same error-code scheme as NA ASU-AOU units service S.pdf - section 3 Troubleshooting, 2 Troubleshooting with error code; Fujitsu Slim duct AR07-09-12-14-18 (ARU-ARYG LL-type equivalent) installation P-N 9381858064.pdf - section 14 Error codes. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
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.