Tunze 3166.50 pump issues

[VJV]

Hi, just bought this and a 9006 skimmer for my 30g Hospital tank and have the following question: the 1605 Turbelle e-jet pump that it comes with does not stay fixed, and the output nozzle rotates until it is pointing inside the comline box, if this makes any sense. I am attaching a picture so that it is clear. How can I stop the pump from rotating? Is it wrongly assembled?

Thanks

It starts in this position....

And ends in this position

 

[rvitko]

OK, my guess is that an O ring is missing, their is a large oring between the bottom retaining plate and the top of the pump. I would double check to see if this is loose in the body or in the packaging.

 

[VJV]

Thanks! Will do.