Coway Airmega 400 how to clean the pre-filters
When the [Pre Wash] indicator is lit, about every 2 weeks.
Steps
- Unplug the air purifier.
- Remove the covers and pre-filters on both sides: press the two tabs at the top of each pre-filter and pull outward.
CAUTION
If you use water to clean the pre-filter, dry the pre-filter in the shade before re-installing it.
Marked CAUTION by the manufacturer Source: Pre-filter, p. 20
- Remove the dust with a vacuum cleaner. If that is not enough, wash the pre-filters gently under water and dry them in the shade.
- Return the pre-filters and covers on both sides.
- Touch and hold the [Pre Wash] button to reset the filter indicator.
The product does not turn on if the right and left covers are installed incorrectly.
Source: Pre-filter Source: Pre-filter, p. 20
Used for
- [Pre Wash] indicator: The pre-filters need cleaning. On the 400S and 400 the button also shows the pre-filter cleaning cycle in levels from 100% down to 0%.
- Air speed from the air outlet is significantly low
Other Airmega 400 procedures
- How to replace the Max2 filtersWhen the [Max2 Change] indicator is lit, about every 12 months.
- How to clean the pollution sensorAbout every 2 months.
- How to adjust the pollution sensor sensitivityWhen the pollution level stays Very unhealthy after more than two hours, or stays Good for more than an hour in a polluted environment.
Sources
- User Manual, Air Purifier 400S/400/300S/300 (English, French). Coway. Document 1216776, revision 003, 88 pages, en-US. cowaymega.com. 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.