Hitachi YUTAKI ATW-YCC-03 Installation And Operation Manual page 31

ELECTRICAL AND CONTROL SETTINGS
9.3.2 LED indication
Name Colour
LED1 Green Power indication
LED2 Red Power indication
LED3 Red Heat pump operation (thermo ON/OFF)
LED4 Yellow Alarm (flickering with 1 sec interval)
LED5 Green Not used
LED6 Yellow H-LINK transmission
LED7 Yellow H-LINK transmission for unit controller
25 PMML0581 rev.1 - 02/2023 - 1000011627
Indication