Hozelock Bioforce Revolution problem

[DogTailRed2]

keeps burping air. No leaks. Hoses all good. Any idea why?
If you have this filter can you confirm if the UV shroud, that's the black plastic tube not the protective glass tube, is meant to spin around.

 

[martin-green]

Have you tried asking Hozelock? They have a contact/email page which you can read if you Click here