Hitachi P-AP160NA1 Installation And Operation Manual page 22

Maintenance
9.2 CLEAN THE FILTER
Clean the air filter according to the following steps:
1 Use a vacuum cleaner or let water flow onto the air filter for
removing the dirt from the air filter.
9.3 RESET OF FILTER INDICATION
After cleaning the air filter, press the "RESET" button. The FILTER indication will disappear and the next filter cleaning time is set.
20 PMML0280A rev.1 - 09/2014
C A U T I O N
Do not use hot water higher than approximately 50ºC
2 Dry the air filter in the shade after shaking off moisture.
3 Do not use cleaner or other chemicals.
4 After the air filter is dried, attach and close correctly to the air
inlet grille.