FX6 Pump Issue

[abl3nc]

Hi all,
New to the forum. Looking for some advice.

My dad has a large fish tank with two FX6 filters. He's had them for a few years and they've run fine ever since now. Yesterday one of the filters started to not pump properly, only pushing water intermittently and the filter is making a knocking sound.

The first thing we tried was just taking it apart and cleaning the impeller and inside of the motor, including the bushing. The issue persists.
We bought a service kit and replaced all the parts (impeller, O-Rings, bushing) but no luck. I put the motor with the issues into the other working FX6 and the same thing.
Every time we did anything and reassembled the filters we made sure there was no air in the system. Eventually, I tried briefly running the motor off of the filter and it spins up fine, however, as soon as I submerged the impeller end in some water it starts stalling erratically again. I take it out of the water and it spins back up again without stalling. I place my finger carefully on the spinning impeller and it starts stalling again due to the slight friction.

It seems like any pressure on the impeller causes it to keep stalling. It seems as though the magnet inside the motor keeps uncoupling from the magnet in the impeller when a load is applied to the impeller.

Is the motor itself busted? Is there anything I can do to remedy it without having to buy a whole new filter/motor? It's a sealed unit so I can't open it up.

Kind regards,
Alex.

 

[Colin_T]

Hi Alex and welcome to the forum

If you tried a new impellor and it still does it, then the motor needs replacing. Before you get a new one, try the new impeller in the other motor that works. See what happens. You might have got a dodgy impellor, unlikely but possible. If it has problems with the new impeller in the other motor then check the new impeller.

You can buy the motor separately but they usually have to be ordered in. Depending on how long your dad has owned the filter for, it might still be under warranty but you would have to check the packaging for details.

Even if you could remove the motor's cover (plastic casing) you wouldn't be able to work on the motor. The electrical components in water pumps and filters are sealed in a plastic resin to stop water getting into them.

 

[abl3nc]

Hi Alex and welcome to the forum

If you tried a new impellor and it still does it, then the motor needs replacing. Before you get a new one, try the new impeller in the other motor that works. See what happens. You might have got a dodgy impellor, unlikely but possible. If it has problems with the new impeller in the other motor then check the new impeller.

You can buy the motor separately but they usually have to be ordered in. Depending on how long your dad has owned the filter for, it might still be under warranty but you would have to check the packaging for details.

Even if you could remove the motor's cover (plastic casing) you wouldn't be able to work on the motor. The electrical components in water pumps and filters are sealed in a plastic resin to stop water getting into them.

Hi Colin,

Thanks for the reply.
The motor is doing it with the original and the new impeller. We did inspect and compare the impeller of the working filter and it looked identical (i.e. the fins, the play in the retaining circle, etc...) but I don't think we actually tried it in the faulty one. That might be the only thing left we can try.

Unfortunately, the warranty ran out last month! (Ordered July 2020 on Amazon) so it looks like our only option is to buy a new one

 

[Colin_T]

If the warranty ran out last month, the manufacturer might give you a new motor because it's just out of warranty. If you write to them and say you think it's a great filter and it has worked really well while you had it (feed them a bit of bs to make it sound like a great product), and then say it's disappointing that it stopped just after the warranty ran out, they might give you another one. Suck up to them and see if they will give you another motor. If they don't, well you need to buy a new one anyway.