Having trouble with a Fluval Fx4

[Jacky82020]

I purchased a used 125 G that came with two Fluval Fx4 canister filters. The system appears to be brand new & is just under 2 years old. One filter is up & running . Seller said both good until he disassembled the setup & says he installed new impellers a a gasket ~3 months ago, adding they should last a year and he is totally mystified as to why one isn’t working here. Everything is properly connected. I texted him photos. He said go ahead and buy another impeller at Amazon which should arrive tomorrow. Amazon also sells the motor for $84. I have never owned a canister filter before & don’t see what it could be other than the impeller or motor, since they wre both properly connected. We even used an air compresser to make sure the hoses weren’t clogged.

Any ideas? Thanks!
The one by the power strip is not working. The other is.

 

[FJB]

You did not give details as to 'how' it is not working (no humming?, no noise at all?, vibration felt by touch? no output, no active intake, etc).
One possibility is something that happened to me once with one my FX6's, after a deep cleaning -
Assuming the motor is working (i.e, one feels vibration by touch), I did this:
After taking the lid off, the clear stand pipe (attached at the opposite end of the clear pipe attached to the lid) was not fully seated in place. Thus a gentle pushing and rotating it until fully seated fixed the problem perfectly. Motor & impeller in perfect order, just not getting fully primed. Worth checking before purchasing an expensive repair kit, which would still not solve the issue if indeed is what I am suggesting. Good luck!

 

[Jacky82020]

There’s a slight vibration when touching the motor. There’s pulsating weak jets of water on the outlets. We did not check the stand pipe but will. Thanks!

 

[Jacky82020]

The clear stand pipe was properly seated. Dang! I felt intermittent vibrations on the motor for a few minutes and then they stopped. This probably corresponded to the weak jets of water . There is a steady hum and constant vibration on the working filter. So , I don’t know if this means the impeller or the motor. If it’s a bad impeller, wouldn’t the motor continue to hum or vibrate or whatever, instead of going cold? Strange it was running fine until he took the tank system apart for us to transport it. He seemed like an honest enough guy, but so did Ted Bundy. Guess I should install the new impeller tomorrow & then order the motor and /or take a closer look at the tune up kits I saw at Amazon?

 

[deeda]

Did you get the owner's manual with either filter? If not, Fluval has them on their website and great instructions for how to service the filter and the pump. It's possible that if the previous owner removed the pump, it wasn't reassembled properly or that he tightened the pump to the canister body incorrectly.

Other possibilities is you didn't fill the canister with enough water before plugging it in or intake/output hoses are switched.

 

[Jacky82020]

Thanks, will def check the Fuval site. Pretty sure enough water was used. both were set up equally but only one has failed.

 

[FahakaPapa]

I just had my return pump stop and lights flashing "service"... took it off, took it apart and cleaned it good and it fired right back up. Sometimes a small piece of detritus will get caught somewhere and stop the whole thing. It was the same for the fluval filters I ran back in the day. My old AC110 hang on backs used to need a little jump start with a screwdriver or something when they stopped too. Would just tap the impeller quick and they would start pumping. I'd take the thing apart and clean it good then see what it does when you start it again. No guarantee just my thought.

 

[Jacky82020]

Thanks, I’ll keep that in mInd. I have several AC110s. Problems with the basket floating up and lifting the ceramic beads out of the water

 

[Jexnell]

Thanks, I’ll keep that in mInd. I have several AC110s. Problems with the basket floating up and lifting the ceramic beads out of the water

That is due to the sponge being dirty and can't flow water thru it anymore. So it pushes the whole assembly up instead. Thoroughly rinse the sponge every couple weeks and will end that problem.

 

[Jacky82020]

I have indeed not cleaned the sponges thoroughly. I fear whacking essential bacteria. But I have multiple AC’s on some of my tanks, so today I will rinse a few better. I rinse them in buckets of conditioned water.