Aqua One External Filter - Can't Get The Impeller Cover Back On!

Looking on the Aqua One website, there is an intruction manual for the Aquis external filter. Is that the one?

Have you done this?

10. Line the filter inlet pipe up with the feeder pipe on the base of the head unit

It sounds like two pipes have to be lined up pretty accurately

11. Press down gently, the bottom of the head unit should be flush with the canister body. Be careful not to jam the power cord in-between the canister and the head unit. Do not force it together! If it feels tight do not apply any pressure to close it simply, remove the head unit and filter baskets and try again.

Is the lid flush with the base? Is there anything caught between the two?

12. Latch and secure the clips

If the lid and body are aligned correctly (the pipes it mentions) and there is nothing preventing the lid sitting flush on the body, it should be possible to latch them together.



Sorry I can't be more help, I only have internals so I have to go by the manual.

Just a thought, do you have the manual?
http://www.aquaone.co.uk/documents/Aquis500-1200_instructions_lowres_new.pdf
The instructions for the Aquis Advance look the same, that's here
http://www.aquaone.co.uk/documents/Aquis550-1250_instructions_lowres_new_001.pdf