Levoit Core 400S air purifier makes an unusual noise while the fan is on
Cause 1 of 3The filter or the surface under the purifier may cause the noise. Source: Troubleshooting, p. 15
First checkMake sure the filter is properly in place with the plastic packaging removed.
Causes and checks
The filter or the surface under the purifier may cause the noise. Source: Troubleshooting, p. 15
- Make sure the filter is properly in place with the plastic packaging removed.
- Make sure the air purifier is operating on a hard, flat, level surface.
The filter may need replacing. Source: Troubleshooting, p. 15
- Replace the filter. See Replace the filter.
The air purifier may be damaged, or a foreign object may be inside. Source: Troubleshooting, pp. 15, 22
Levoit Customer Support Stop using the air purifier and contact Levoit Customer Support: 1-888-726-8520. Do not try to repair it. Contact: 1-888-726-8520 or support.levoit.com.
All 3 causes checked. Contact Levoit Customer Support: 1-888-726-8520.
Service
If the checks above do not clear it, contact Levoit Customer Support: 1-888-726-8520, support.levoit.com. United States (Monday to Friday, 9:00 am to 5:00 pm PST/PDT). Source: Customer Support, p. 22
Other Core 400S problems
- Air purifier will not turn on or respond to buttons2 causes in the manual. First: the purifier gets no power, or the power cord is damaged.
- Airflow is significantly reduced3 causes in the manual. First: airflow is significantly reduced.
- Strange smell coming from the air purifierStrange smell coming from the air purifier.
- Poor air purification quality3 causes in the manual. First: the room is larger than 403 ft² (37 m²), so air purification takes longer.
- Air quality indicator always stays red2 causes in the manual. First: the AirSight Plus Laser Dust Sensor may need to be cleaned. Dust blocking the sensor affects its accuracy.
- Air quality indicator always stays blue when the air is poorThe AirSight Plus Laser Dust Sensor detects airborne particles but cannot detect gas.
- Purifier will not connect to the VeSync app5 causes in the manual. First: the phone's Bluetooth is off, or the phone is connected to another Bluetooth device.
- Purifier shows offline in the VeSync app2 causes in the manual. First: the purifier is offline.
Sources
- User Manual, Core 400S smart air purifier. Arovast Corporation. Document HEAPAPLVSUS0162Y, revision A1-241202, 24 pages, en-US. levoit.com (PDF). Listed on the manufacturer's support page. Retrieved 13 November 2026.
Page numbers are the numbers printed in the manual. Where this page and the manual differ, follow the manual.