[vanish]

I set up a brand new Sunsun 304b about a week ago on a new tank. Its in the dining room, so I wanted something very quiet to replace the aging noisy extra HOBs I have. Well, so far it has failed in that regard. The hum is fine, I don't mind a little background noise, but it has a constant clicking sound.

I do not believe the issue is air in the system, as I have reset it several times and shaken until my arms were tired (ITS HEAVY!). The impeller housing O-Ring looks too big to me (fits loosely, photo attached showing original )), but I tried replacing it with a different one and same issue, but the replacement wasn't an exact size either, it may have been too small. I swear the impeller housing (the part you twist off to get to the impeller) does not sit flat.

I checked the impeller itself and that looks fine.

Here is a video showing the sound when I run it (just for a few seconds) empty:

https://www.youtube.com/watch?v=O4spqA9LJQM

and another video showing it when running on the tank:

https://www.youtube.com/watch?v=jCcqXuqqYeg

Should I just attempt to send the darn thing back? I'm extremely sensitive to non-repetitive sounds.

 

[JasterMake]

I know this is ancient but I just got a 304b that sounded very similar. if someone else has this problem this is something else to try.

There are 4 screws on the head unit and I tightened them up. Be careful because you can easily strip the plastic if you muscle it. They did not feel loose when I did it but it shut up the rattle. Now it just hums.