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15 Flashes (Outdoor Unit)

Outdoor Unit LED 15 Flashes — Compressor start up error (permanent stoppage)

Fujitsu · Air to Water Heat Pumps

What does 15 Flashes (Outdoor Unit) mean?

The LED on the outdoor unit flashes 15 times. This indicates a critical and persistent error during the compressor's startup sequence, resulting in a permanent system stoppage.

Common Causes

  • Faulty compressor or its starting components.
  • Issues with the inverter module that controls the compressor.
  • Electrical problems affecting compressor motor windings.
  • Internal communication error preventing proper startup.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Power cycle the heat pump system by turning off the main breaker for at least one minute, then restoring power.

  2. 2

    Ensure stable and consistent power supply to the outdoor unit.

  3. 3

    If the error persists, contact a qualified technician immediately, as this error often points to significant issues with the compressor or inverter system requiring specialized repair.

Browse all codes in this manual (59)
Verified technical data. Last updated: April 2026

Related Faults

1 Flash (Outdoor Unit)Outdoor Unit LED 1 Flash — Serial forward transfer error10Fault 10 — Outdoor sensor error11Error 11 (1 Green, 1 Red Flash) — Communication error between Hydraulic and Outdoor unit
Source: Fujitsu Air to Water Heat Pumps
Open Manual (Page 9)Search more codes in this manual