CodeRegistry
Brands
  1. Home
  2. Fujitsu
  3. 410A Multi-Zone Mini-Split Systems
  4. Operation 3 Times / Timer 04
About·Privacy·Terms

CodeRegistry — Your global library for technical solutions.

For your safety: always follow the equipment manufacturer’s official manuals. CodeRegistry is an independent help site and is not affiliated with the brands listed here.

Operation 3 Times / Timer 04

Operation LED blinks 3 times and Timer LED blinks 3 times (04) — Indoor heat exchanger thermistor error.

Fujitsu · 410A Multi-Zone Mini-Split Systems

What does Operation 3 Times / Timer 04 mean?

The thermistor sensing the indoor heat exchanger temperature is reporting an abnormal reading.

Common Causes

  • The indoor heat exchanger thermistor is open (disconnected) or shorted (faulty connection).
  • The controller PCB is defective.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Power off the unit at the circuit breaker.

  2. 2

    Visually inspect the indoor heat exchanger thermistor for any visible damage or loose connections.

  3. 3

    If the error persists, a technician should check the thermistor's resistance or the controller PCB.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

6 Times, 4 Times Continuous (64)6 Times, 4 Times Continuous (64) — Active Filter / PFC Circuit error6 Times, 5 Times Continuous (65)6 Times, 5 Times Continuous (65) — IPM error / Trip terminal L error7 Times, 1 Time Continuous (71)7 Times, 1 Time Continuous (71) — Discharge thermistor error
Source: Fujitsu 410A Multi-Zone Mini-Split Systems
Open Manual (Page 25)Search more codes in this manual