In Hitachi split air conditioners, a white light typically indicates that the unit is operating in normal mode. It means that the air conditioner is functioning properly and maintaining the desired temperature set on the control panel.
However, it's important to note that different models of Hitachi air conditioners may have slight variations in their indicator lights. For a more accurate understanding, it's recommended to refer to the specific model's user manual or consult the manufacturer's customer support for detailed information on the meaning of the indicator lights.