Ako F3

What does Ako F3 mean?

F3 defines the status of the evaporator fans during defrost cycles. Setting F3 to 0 stops the fans during defrost (recommended for electric resistance, cycle reversal, or hot-gas defrost to prevent warm air from circulating into the cold room). Setting F3 to 1 keeps fans running during defrost. F3 applies only to active defrost types; it has no effect during off-cycle defrost. This is a commissioning parameter, not a fault.

Symptoms

• If F3 = 0 (fans off during defrost): fans de-energize at the start of every defrost cycle.
• If F3 = 1 (fans on during defrost): fans run throughout the defrost period.
• Incorrect F3 setting for electric defrost may circulate warm defrost air into the cold room, raising product temperatures.
• Fans running during hot-gas defrost (F3=1) may cause warm air to reach the cold room through the evaporator discharge.

Common causes

• F3 parameter configured incorrectly for the defrost type during commissioning.
• Defrost type changed (e.g., from off-cycle to electric resistance) without updating F3.
• Factory default F3 value inappropriate for the installed defrost system.

Diagnostic steps

1. 01

   Identify the defrost type installed

   Confirm whether the system uses off-cycle, electric resistance, hot-gas, or cycle-reversal defrost. F3 has no function during off-cycle defrost; for all active defrost types, F3 should be 0 (fans off during defrost).

2. 02

   Check the current F3 value

   Enter the parameter menu and read the current F3 setting. Verify it matches the commissioning specification for the installed defrost type.

3. 03

   Adjust F3 if incorrect

   Set F3 = 0 for electric, hot-gas, or cycle-reversal defrost systems. Save the parameter. F3 = 1 is generally only appropriate for specific cases where air circulation during defrost is required.

4. 04

   Verify fan behavior during next defrost cycle

   Observe the fans when the next defrost cycle starts. Confirm they stop (F3=0) or run (F3=1) as configured. Check that cold-room temperature does not spike abnormally during defrost.

5. 05

   Document F3 setting

   Record the confirmed F3 value in the commissioning record alongside the defrost type for future maintenance reference.

When to call a professional

Call a licensed refrigeration technician if cold room temperatures are spiking during defrost cycles despite a correct F3 setting, or if the defrost system type is being changed. Changing from off-cycle to active defrost requires heater installation and electrical work, and adjusting hot-gas defrost valves requires certified refrigerant handling.