Every time you change the filter, the filter light will reset automatically. Related articles BreatheSmart 75i - Troubleshooting - Filter Light Reset BreatheSmart 75i V2 - Troubleshooting - Particle Sensor Light Not Changing Colors BreatheSmart 75i V2 - Troubleshooting - Buttons Not Working Product Manuals BreatheSmart 75i V2 - Troubleshooting - No Power