Overview
If the defrost symbol appears on your controller display (the snowflake with lines and power icon as shown below), it indicates that your system is currently performing an automatic defrost cycle.
This is a normal part of heating operation designed to protect your outdoor unit and maintain efficiency.
1. Why Defrost Mode Happens
During heating operation, the outdoor unit absorbs heat from the outside air.
In cold or humid conditions, moisture in the air can freeze on the outdoor coil, reducing efficiency.
To correct this, the system automatically enters a defrost mode to remove the frost buildup.
While in this mode:
The outdoor fan stops.
The indoor fan may also stop or blow cold air briefly.
The defrost symbol appears on the controller screen.
The system will resume normal heating automatically once the coil temperature returns to normal.
2. Typical Duration
The defrost cycle usually lasts between 4 and 15 minutes, depending on outdoor conditions.
This process may occur several times per hour when the outdoor temperature is low or humidity is high.
3. What You’ll See on the Controller
During automatic defrost operation, the following symbol will appear:
Defrost Indicator:
And the controller may display a similar screen during operation:
This icon indicates the system is temporarily paused while the outdoor unit clears frost from the coil.
4. No Action Required
Defrost mode is fully automatic — no manual input is needed.
Once the outdoor unit has defrosted, the symbol will disappear and heating will resume automatically.
Note:
The room may feel slightly cooler during this time. This is normal and does not indicate a fault.
5. When to Contact Service
If:
The defrost symbol stays on for longer than 20 minutes,
The unit fails to return to heating mode, or
You notice no heat output for an extended period,
then it may indicate an issue such as a sensor fault or airflow obstruction.
In that case, please contact Fujitsu Assist Technical Support or your service agent.