Honeywell HDS18SS User Manual page 13

02 Rotate the filter insert counterclockwise to unfasten and detach the filter insert.
03 Remove the fine filter. (flat rectangle)
04 Remove any dirt or other remains from the filters, and then rinse them under
running water.
05 Reassemble the filters in the reverse order of the dissasembly, replace the filter
insert, and rotate clockwise to the close arrow.
CAUTION If the filter is not closed properly, its preformance will be decreased.
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