FAQ: Split Systems What is defrost function?
When the outdoor temperature is very low and humidity is high, frost may form on the outdoor unit during heating operation, which could affect its performance.
When frost forms on an outdoor unit, the air conditioner stops running and the defrosting circuit runs automatically for up to 15 minutes.
While defrosting is in progress, the Operation indicator blinks on the indoor unit.
The video shows how an indicator blinks on model ASTG24KMCA.