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Fujitsu / AIRSTAGE H-series

Fujitsu CHECK RUN status display

Check run is a setup/service mode used to verify indoor-unit wiring and piping order. Flashing MONITOR LEDs during this mode are progress/result indications, not fault codes by themselves.

Urgency
informational
Verified
Jul 30, 2026
Fix path
Not an error

What it means

Check run is a setup/service mode used to verify indoor-unit wiring and piping order. Flashing MONITOR LEDs during this mode are progress/result indications, not fault codes by themselves.

Urgency

Not an error

This is a normal status or service-mode indication, not an error, unless comfort is poor, the status never clears, or a separate SW1 fault code appears.

Likely causes

    Homeowner fix

    If a technician started check run, let them finish. If the system seems stuck in check run, turn it off once and call the installing contractor.

    When to call a pro

    Call the installer if check run results do not match the installed indoor units, or if the display will not return to normal.

    Repair vs replace

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

    Your Fujitsu model

    AIRSTAGE H-series model pages in the Fujitsu catalog help compare this repair path with current replacement options.

    Parts for this line

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

    Open parts page

    For your technician

    Technician note: Section 14-1 starts check run by pressing CHECK for 3 seconds or more and displays connected indoor units before the run. Page context: Fujitsu maps this display to the AIRSTAGE H-series line; source: Fujitsu AOUH18-45KWAS/KWAH R-32 Design & Technical Manual.

    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

    If a technician started check run, let them finish. If the system seems stuck in check run, turn it off once and call the installing contractor.

    Manual trigger

    Check run is a setup/service mode used to verify indoor-unit wiring and piping order. Flashing MONITOR LEDs during this mode are progress/result indications, not fault codes by themselves.

    Related codes

    Source

    Fujitsu AOUH18-45KWAS/KWAH R-32 Design & Technical Manual
    Section
    Section 14-1 Check run
    Page
    PDF pages 246-250; manual pages 240-244

    Short quote: "Press the CHECK switch for 3 seconds or more"

    Sourced Jul 2026

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