Re-Assembling the Unit
1. Place the foam 'O'-ring into the unit, and place it around the filter collar right in front of the Motor Assembly (if a new foam 'O'-ring is available, use it in place of the old one)
2. Place the Filter Assembly into the unit, onto the Motor Assembly and firmly twist the Filter Assembly clockwise until the filter is locked tight.
3. Replace the front door by sliding it into place top end first, then lift up and in to align the door into position in it's track, then let it slide down into it's fully closed position.
Replace safety screw if one was removed while opening the unit.
4. Plug the unit back in, and turn it on.