Fujitsu SW1 CODE DISPLAY status display

What it means

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.

Urgency

Likely causes

1. Indoor/outdoor communication wiring or terminal problem
2. Loose low-voltage connector after service or vibration
3. Power interruption during the control handshake
4. Indoor or outdoor control board fault after wiring is verified

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.

When to call a pro

Call a licensed HVAC technician if any fault code is shown. Give them the exact SW1/MONITOR code and the indoor unit letter if one was indicated.

Repair vs replace

This is a status display, not a repair-or-replace decision.

• Fujitsu AIRSTAGE H-series Compact Cassette 9,000 BTU R-32 208/230V (ACUH09KUAS / AOUH09KUAS1)

  AIRSTAGE H-series

• Fujitsu AIRSTAGE H-series Compact Cassette 12,000 BTU R-32 208/230V (ACUH12KUAS / AOUH12KUBS1)

  AIRSTAGE H-series

• Fujitsu AIRSTAGE H-series Floor-Mounted Console 12,000 BTU R-32 208/230V (AGUH12KUAS / AOUH12KUBS1)

  AIRSTAGE H-series

• Fujitsu AIRSTAGE H-series Mid Static Duct 12,000 BTU R-32 208/230V (ARUH12KUAS / AOUH12KUBS1)

  AIRSTAGE H-series

Parts for this line

The parts catalog for Fujitsu AIRSTAGE H-series lists 6 sourced replacement parts for this product line.

For your technician

Technician note: Section 14-3 says to briefly push SW1 while the error is occurring; A/C/F/J/P/U map to 10/11/12/13/14/15 blinks. Page context: Fujitsu maps this display to the AIRSTAGE H-series line; source: Fujitsu AOUH18-45KWAS/KWAH R-32 Design & Technical Manual; display convention: match the letter S, letter W, one, letter C, letter O, letter D, letter E, letter D, letter I, letter S, letter P, letter L, letter A, and letter Y marker exactly before comparing neighboring codes.

Which systems show it

• 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.

Related troubleshooting

Use the symptom guide alongside the exact display code if the unit is flashing, cycling, or showing comfort symptoms.

Reset note

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.

Manual trigger

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.

Related codes

Source

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