Error code · Air Purifier

LG Air Purifier Message Check Filter: Filter Sensor Alert

Medium · inspection needed

Code: Check filter
Appliance: Air Purifier
Brand: LG
Warranty: 30-day workmanship

What Check filter means

Check filter appears on the LG PuriCare 360 Alpha air purifier when the filter-life sensor, which measures differential pressure, finds something unusual. It is often seen at first use, when the filter is still in its plastic wrapping or has not been installed. The owner sees the message and the purifier may not start its normal cleaning cycle until the filter reading looks right. The message points to the filter position and wrapping first, before any sensor concern.

Common causes of Check filter

Filter still in its plastic wrapping
Filter not installed or not fully seated
Filter installed upside down
Filter-life sensor reading outside the expected range

✓ One safe check you can try

1. Turn the purifier off and unplug it. 2. Remove the filter and take off all plastic wrapping. 3. Seat the filter again with the handle facing up. 4. Close the cover, plug the unit in, and start it to see whether the message returns.

! Why to stop there

If the message returns with the filter unwrapped and seated correctly, we test the filter-life sensor and its connection.
We check that the airflow path is clear before blaming the sensor.
You get the finding and a written price first.

Opening a panel yourself does not automatically cancel a manufacturer warranty, but it can cause accidental damage, and some manufacturers set their own service conditions. Check your warranty terms, or ask us, before deciding.

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Other Air Purifier codes

Filter replacement lampLG Air Purifier Filter Replacement Lamp: Use-Time Reminder

Check filterCheck filter questions

Why does Check filter show on a brand new purifier?

A new filter often arrives wrapped in plastic. With the wrapping on, air cannot pass, so the pressure sensor reports an abnormality. Removing the plastic usually solves it.

What does the handle position matter?

The filter needs to sit in the right direction, with the handle up, so the airflow passes through it correctly. A filter turned the wrong way can trigger the same message.

Does the message mean the filter is worn out?

Not necessarily. The filter replacement lamp tracks use time separately. Check filter is about an abnormal sensor reading, which is often a wrapping or seating matter.

Book a visit

Still seeing Check filter?

A technician diagnoses it on site and gives you the price in writing before any work starts.

(713) 597-5662