had the bits accessible from the inside all out again.
filter are clear.
Under the grille there are 3 channels (approx 1/2" diameter). One (@ 9pm)
is for pumping out. Dont know about the other 2 - but they are both clear.
below the grille are 2 small (~2mm) holee which are clear - at least whe
poked with a nylon bristle brush down the hole.

How do i get at the pump ?