Hi there,
Thanks for your contact.
According to the user manual, we need to reset the air purifier after having a replacement of filters.
If your purchased air purifier is AirMic4S Air Purifier, please press the" button of filter light" for 3 seconds(not 3 times).
And if your purchased air purifier is AirMax8L Air Purifier, please press the "sleep mode "for 3 seconds as well.
If your purchased air purifier is AirMax10L Air Purifier, please press the" button of filter light" for 3 seconds as well.
Hope this message can help you.
If not, it's our great honor to offer further efficient aids.
Best regards,
Mile
Okaysou