How do I install and reset the PureAir filter indicator?

Remove the dust filter, insert the PureAir filter (sold separately) in the reserved space behind the dust filter, then reinstall the dust filter and air inlet grille — if installed correctly, the PureAir filter indicator will glow white. After 1,440 hours of operation, the indicator will turn red to signal replacement is needed. To reset the indicator after replacing the filter, hold the Sleep button for 3 seconds. (Page 17)