Tunze 9410 DC- operating normally?

[Mark Hyman]

Could someone familiar with the 9410 DC skimmer please confirm that at 20-30% on the controller, the impeller is supposed to turn on for a few seconds and then off for a few seconds vs the speed slowing down? The bubble level keeps fluctuating as the unit turns on and off, and the alternating noise of the pump cycling on and off is a bit annoying. I recorded a couple of on/off cycles to illustrate. The pump was loud when first set up; I think the needle wheel was scraping the lid, but that seems somewhat better after I disassembled and made sure the bearings were seated.

I've heard great things about this skimmer and want to give it a chance. Thanks!

 

[rvitko]

It should not turn on and off. What I see in the video seems to show a steady water flow so the pump does not seem to be turning off, the air flow is surging, if you are sure the bearings are fully seated I can see 3 possibilities:

1)It is possible water is being drawn in through the air intake intermittently which a normal feedback loop, but means something is not installed correctly (pipe or basket too high or water level, I cannot see that very well from this angle) a silencer leak is also possible or a surfactant is in the water and causing this auto shut down loop which is an intentional design feature to avoid overflowing.

2)A damaged impeller, A lot of times what has happened is a bearing was loose, the impeller shaft breaks, especially the bottom one, and the play is what causes this problem, sometimes the needlewheel has broken free of the magnet and the magnet turns without the needlewheel or it slips periodically. (we can send an impeller if this is the case)

3) Impeller is rubbing the housing due to a motor assembly issue, the motor coil can be mispositioned, this causes the impeller to ride high and rub and jam on the impeller housing, in this case we would exchange the pump, typically in this scenario there is a lot of noise, the pump also has a minimal flow increase as you increase speeds and will only tend to skim at high speed and be very loud.

 

[1ocean]

I have one in my 300 along with a reef octupus 300int. The tunze should stay on and run quite. Sometimes it may made a little rattling noise from the lid but that is about it. They are awesome skimmers. Sounds like you got a bad assembled one or a defective part.

 

[Mark Hyman]

It should not turn on and off. What I see in the video seems to show a steady water flow so the pump does not seem to be turning off, the air flow is surging, if you are sure the bearings are fully seated I can see 3 possibilities:

1)It is possible water is being drawn in through the air intake intermittently which a normal feedback loop, but means something is not installed correctly (pipe or basket too high or water level, I cannot see that very well from this angle) a silencer leak is also possible or a surfactant is in the water and causing this auto shut down loop which is an intentional design feature to avoid overflowing.

2)A damaged impeller, A lot of times what has happened is a bearing was loose, the impeller shaft breaks, especially the bottom one, and the play is what causes this problem, sometimes the needlewheel has broken free of the magnet and the magnet turns without the needlewheel or it slips periodically. (we can send an impeller if this is the case)

3) Impeller is rubbing the housing due to a motor assembly issue, the motor coil can be mispositioned, this causes the impeller to ride high and rub and jam on the impeller housing, in this case we would exchange the pump, typically in this scenario there is a lot of noise, the pump also has a minimal flow increase as you increase speeds and will only tend to skim at high speed and be very loud.

Thanks for this- really appreciate the quick follow up! I’ll check it tonight but pretty sure there’s no water in the air line. The other possibilities would also be consistent with the pump being so loud initially (and still somewhat). I purchased from Aquacave (they’re basically next door to me); should I work with them or touch base with you/Tunze directly?

Best,
Mark

 

[rvitko]

We would send or exchange the part under warranty, we are in Texas, the hassle would be minimal, just let me know what you find on the impeller.

 

[Mark Hyman]

We would send or exchange the part under warranty, we are in Texas, the hassle would be minimal, just let me know what you find on the impeller.

Thanks; PMed you to follow up.