Installation of inner cover

  1. Remove the inner cover from the frame.
  2. Stick the sealing strip all around the connection socket of the frame.
  3. Push the connection socket of the frame into the wall sleeve and fix the frame to the interior wall.
  4. Ensure that the air filter unit (inner filter holder, air filter and outer filter holder) is correctly engaged at the 4 corner points in the inner cover.
  5. Carefully press the entire cover unit onto the frame until it clicks into place (ensure correct slider function).