Noisy fluval 306

Hi everyone,
I’ve just got a second hand fluval 306 external filter and as soon as we connect it to the tank it becomes very noisy and rattles. I’ve tried running it in a bucket and it doesn’t make a noise but as soon as I connect it back up to the tank it starts humming loudly again! Struggling to find a cause, I’ve tried making sure there’s no air in the tubes, priming, making sure all the seals are working but it’s still making the noise.
Anyone have any advice?
Thanks

 

Have you checked your impeller for a broken fin,missing rubber grommet or grit or foreign object in propeller housing

 

Have you checked your impeller for a broken fin,missing rubber grommet or grit or foreign object in propeller housing

Yep, I’ve checked all that and nothing seems to be amiss- it’s starting to drive me crazy now!

 

Its still pumping a full bore

 

Hi everyone,
I’ve just got a second hand fluval 306 external filter and as soon as we connect it to the tank it becomes very noisy and rattles. I’ve tried running it in a bucket and it doesn’t make a noise but as soon as I connect it back up to the tank it starts humming loudly again! Struggling to find a cause, I’ve tried making sure there’s no air in the tubes, priming, making sure all the seals are working but it’s still making the noise.
Anyone have any advice?
Thanks

Give it a few days it should quite down. I have that filter and after I clean it out it’s a bit rattly for a few days until all the air bubbles have worked their way out. Try rocking it side to side too to get air locks out.failing that you may need a new impeller and shaft as after a while the ceramic shaft wears a bit so the impeller isn’t a tight fit making it move side to side.