Levoit Core 400S smart air purifier
- Category
- Air purifiers
- Model number
- Core 400S
- Region
- United States
- Verified
- Error E1
- Check Filter Indicator
- Air purifier will not turn on or respond to buttons
- Airflow is significantly reduced
- Air purifier makes an unusual noise while the fan is on
- Strange smell coming from the air purifier
- Poor air purification quality
- Air quality indicator always stays red
- Air quality indicator always stays blue when the air is poor
- Purifier will not connect to the VeSync app
- Purifier shows offline in the VeSync app
- How to reset the Check Filter Indicator
- How to replace the filter
- How to clean the pre-filter
- How to clean the AirSight Plus Laser Dust Sensor
- How to disconnect from Wi-Fi and restore defaults
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Error codes
| Code | Meaning | Checks |
|---|---|---|
| E1 | The motor has malfunctioned. | Checks |
| Check Filter Indicator | A reminder to check the filter. It should turn on at about 12 months, sooner if you run the purifier frequently and later if you do not use it often. | 3 causes |
E1
Error code "E1" on the display. The motor has malfunctioned.
Levoit Customer Support Contact Levoit Customer Support: 1-888-726-8520 or support@levoit.com. Contact: 1-888-726-8520 or support.levoit.com.
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.
- Air purifier makes an unusual noise while the fan is on3 causes in the manual. First: the filter or the surface under the purifier may cause the noise.
- 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.
Strange smell coming from the air purifier
Strange smell coming from the air purifier. Source: Troubleshooting, pp. 15, 22
- Clean the filter, or replace it if necessary. See Clean the pre-filter.
- Make sure not to use the air purifier in an area with high humidity or while diffusing essential oils.
Levoit Customer Support If the smell continues, contact Levoit Customer Support: 1-888-726-8520. Contact: 1-888-726-8520 or support.levoit.com.
Air quality indicator always stays blue when the air is poor
The AirSight Plus Laser Dust Sensor detects airborne particles but cannot detect gas. Source: Troubleshooting (cont.), p. 16
- Check that no gas is polluting the air.
How-to
- How to reset the Check Filter IndicatorAfter replacing the filter while the indicator is lit, or after replacing it before the indicator lit.
- How to replace the filterWhen the Check Filter Indicator lights and the filter is clogged, noisy or loses airflow, or every 12 months.
- How to clean the pre-filterEvery 2 to 4 weeks.
- How to clean the AirSight Plus Laser Dust SensorEvery 3 months, or when the air quality ring stays red. More often in a dusty environment.
- How to disconnect from Wi-Fi and restore defaultsTo restore the purifier's default settings and disconnect it from the VeSync app.
Maintenance
| Task | When | Source |
|---|---|---|
| Clean the pre-filter with a soft brush or vacuum hose | Every 2 to 4 weeks | Source: Care & Maintenance, p. 12 |
| Replace the filter | 12 months recommended | Source: Care & Maintenance (cont.), p. 13 |
| Clean the AirSight Plus Laser Dust Sensor with a vacuum cleaner | Every 3 months | Source: Care & Maintenance (cont.), p. 14 |
| Unplug, then wipe the outside with a soft, dry cloth, or a damp cloth dried at once, and vacuum the inside. No abrasive chemicals or flammable cleaning agents. | Source: Care & Maintenance, p. 12 |
Settings
| Setting | Options | Default | Notes | Source |
|---|---|---|---|---|
| Fan speed | Low (1 indicator), medium (2), high (3), turbo (4) | Low when the purifier is switched on | Turbo is the loudest and cleans fastest. Run it for 15 to 20 minutes after smoke before dropping to a lower speed. | Source: Using Your Smart Air Purifier, p. 7 |
| Auto Mode | Tap the Auto Mode button | Fan speed follows the AirSight Plus reading: blue (PM2.5 0–35 µg/m³) Sleep Mode, green (36–75) low, orange (76–115) medium, red (above 115) high. Auto Mode does not use turbo. After switching on, the ring stays blue for 5 seconds while the sensor reads the air. | Source: Using Your Smart Air Purifier (cont.), p. 8 | |
| Quiet Auto Mode and Efficient Auto Mode | Choose in the VeSync app | Quiet Auto Mode uses medium fan speed instead of high or turbo, even when the air quality is poor. Efficient Auto Mode lets you choose the size of the area to purify. It uses turbo for a designated amount of time based on ACH 1 and the room size, then adjusts the fan speed to the detected air quality. | Source: Using Your Smart Air Purifier (cont.), p. 10 | |
| Sleep Mode | Tap the Sleep Mode button | Uses a fan speed lower than low and turns the display off after 3 seconds. | Source: Using Your Smart Air Purifier (cont.), p. 8 | |
| Timer | 1 to 12 hours on the purifier in 1-hour steps; 1 to 24 hours in the VeSync app | The display switches from the PM2.5 reading to the selected time, then back after 5 seconds without a tap while the timer counts down. Tapping the Timer button shows the remaining time, rounded up to the nearest hour. The purifier remembers the last timer length but does not resume the timer when turned back on. | Source: Using Your Smart Air Purifier (cont.), p. 9 | |
| Display Lock | Hold the Display Lock button for 3 seconds | Buttons do not respond to taps. Settings can still be changed through the VeSync app. | Source: Using Your Smart Air Purifier (cont.), pp. 9, 10 |
Parts and consumables
| Item | Replace or refill | Specification | Source |
|---|---|---|---|
| 3-Stage Original Filter | 12 months recommended | Pre-filter, main filter and activated carbon filter; pre-installed. | Source: Package Contents; About the Filter; Care & Maintenance (cont.), pp. 2, 11, 13 |
Specifications
Smart air purifier for the VeSync app with an AirSight Plus laser dust sensor, a PM2.5 display, a colour air quality ring and four fan speeds including turbo. Source: Controls & Display; Using Your Smart Air Purifier (cont.), pp. 5, 8
The Check Filter Indicator is the filter-change light. It lights after about 12 months of use, depending on how often the purifier runs, and the Check Filter Indicator Reset button clears it. Source: Controls & Display; Care & Maintenance, pp. 5, 12
E1 on the display means the motor has malfunctioned. Source: Troubleshooting (cont.), p. 16
| Electrical | AC 120 V, 60 Hz, rated power 38 W | Source: Specifications, p. 2 |
|---|---|---|
| Operating conditions | 14–104 °F (-10–40 °C), humidity below 85% RH | Source: Specifications, p. 2 |
| Noise level | 24–52 dB | Source: Specifications, p. 2 |
| Dimensions (W × D × H) | 10.8 × 10.8 × 20.5 in (27.4 × 27.4 × 52 cm) | Source: Specifications, p. 2 |
| Weight | 11 lb (5 kg) | Source: Specifications, p. 2 |
| Room size for normal purification speed | Up to 403 ft² (37 m²); larger rooms take longer | Source: Troubleshooting (cont.), p. 16 |
| Clearance | At least 15 in (38 cm) on all sides | Source: Getting Started, p. 6 |
Recalls
No exact-model match for Core 400S in the U.S. Consumer Product Safety Commission recall database, checked . Recalls can name model families, so also check current recalls for Levoit.
Service 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
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.
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