Fujitsu · Heat pump

23 Combination error

Medium severity 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)

What the control is telling you

Outdoor unit received refrigerant / model information from an indoor unit that is not an allowed match. Indoor lamps: OPERATION (green) flashes 2x, TIMER (orange) flashes 3x, ECONOMY (green) flashes fast nonstop; wired remote shows 23.

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

Incompatible indoor unit connected

Test and repair steps

Check the model of each connected indoor unit against the outdoor unit's approved list.
If correct, replace the outdoor main PCB.

Settings for these units

Operating range and service space · Fujitsu multi-zone outdoor 18/24 type

Other codes on the same units

16 Peripheral unit / transmission PCB connection error
18 External communication error (WLAN / option adapter)
21 Address / refrigerant circuit setting error
22 Indoor unit capacity error
24 Connection unit number error
26 Indoor unit address setting error
27 Primary / secondary unit setup error
29 Connection unit number error (wired remote system)

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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.