01 • Atlantic • Takao / Zenkeo (Mural)
Fault Code 01 Atlantic Air Conditioning: Communication Problem (Serial Link)
On Atlantic wall-mounted air conditioners (Fujitsu-based), fault code 01 (often indicated by flashing: 1 Timer flash) indicates a break in the serial link.
Proof status : Manufacturer reference needed for the exact range
Source: Atlantic / Fujitsu Service Manual

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Founder of AskMarcel.app. Sheets are written from manufacturer documentation; the reference is shown when it has been verified.
In brief
Fault code 01 on Atlantic Takao / Zenkeo (Mural) means: On Atlantic wall-mounted air conditioners (Fujitsu-based), fault code 01 (often indicated by flashing: 1 Timer flash) indicates a break in the serial link. Most common cause: Interconnection cable (3-core pilot wire) cut, poor connection, or no power supply to the outdoor unit. First action: Switch off the air conditioning circuit breaker for 3 minutes.. Call a registered engineer if the fault returns after basic checks or involves refrigerant work (F-Gas registered engineer required).
According to the Atlantic / Fujitsu Service Manual, fault code 01 indicates a break in the serial link between indoor and outdoor units.
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Atlantic code 01: Marcel picks this code up for Takao / Zenkeo (Mural) and guides you, with the manufacturer reference when one exists.
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What does fault code 01 on Atlantic mean?
On Atlantic wall-mounted air conditioners (Fujitsu-based), fault code 01 (often indicated by flashing: 1 Timer flash) indicates a break in the serial link.
Interconnection cable (3-core pilot wire) cut, poor connection, or no power supply to the outdoor unit.
Symptoms
- The air conditioner does not start
- The flaps remain closed or open and then close
Diagnosis
1. Electrical Reset
- Switch off the air conditioning circuit breaker for 3 minutes.
- If the fault returns immediately, check the cable between the two units.
Repair and return to service — Atlantic fault 01
Repair the wiring or replace the electronic PCB if the signal no longer passes.
When should you call an F-Gas engineer?
Contact an F-Gas registered engineer if the fault returns after basic checks, involves refrigerant charging, or requires PCB or compressor replacement on Atlantic Takao / Zenkeo (Mural).
Field context
Fault code 01 most often appears during air conditioning operation, particularly on Takao / Zenkeo (Mural). The air conditioner does not start.
Frequently asked questions
What does code 01 mean?
On Atlantic wall-mounted air conditioners (Fujitsu-based), fault code 01 (often indicated by flashing: 1 Timer flash) indicates a break in the serial link.
What is the most common cause of 01?
Interconnection cable (3-core pilot wire) cut, poor connection, or no power supply to the outdoor unit.
How do you diagnose 01 in the field?
Electrical reset: Switch off the air conditioning circuit breaker for 3 minutes.
How do you resolve fault 01?
Repair the wiring or replace the electronic PCB if the signal no longer passes.
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