Do you guys have problems with Eheim pumps ?
 

I was just wondering if you guys have problems with eheim pumps making a lot of noise (like this ).
a lot of people in germany report problems like this and they think its a 50/60 hz problem with the magnet, and eheim putting wrong magnets in their pumps.

I live in USA, and mine runs great... Eheim 1250.. very quiet once you bleed the line properly. :)

just got it yesterday.

sounds like that thing isnt primed. tell the person who ever it is to SUCK! on the other side of the pump . and keep the water on or below the water res.

Sonix

air is not the problem here.
a lot of ppl have those problems and even with the pump fully underwater it is the same sound.

the 50/60hz thing could be valid I guess.

are they running with incredibly restrictive system? I've seen a few pumps developing rattles under really level load.

That MP3 you linked to sounds exactly like the powerheads in my aquarium do when they get air in them after a maintenance cycle until I get all the air out (side note - they are completely submerged 1 foot down in 80 - 90 gallons of water). That sound is from the impeller.

As Brad said, excessive back pressure can also cause impeller rattle. From what I've seen/read a fair number of systems in Europe are pretty restrictive. 3/8" is "large" tubing and 1/4" tubing isn't uncommon. Some of the water blocks look to be pretty restrictive too.

I've also noticed on my aquariums that higher back pressure makes it much harder to get all the air out of the impeller cavity. With high back pressure the air bubbles tend to stay attached to the impeller.

To see if it is either air or too much back pressure, put the pump in a large container of water (15 liters or so) with the pump sitting on its end so that both intake and exhaust are "up". Don't have any tubing attached to the pump. Start the pump and gently shake it for a minute while it's running (shaking helps to break any air bubbles loose).

If the sound goes away, turn off the pump and then add your tubing to the pump's outlet (try to attach it without removing the pump from the water). Then turn it back on and see how if the sound returns. If it doesn't, then grab the end of the tubing (output end) and "pinch it" down as far as you can to increase the back pressure on the pump and see if the sound returns.

For a final test if you make it this far without the impeller rattling, connect the tube to the inlet of the pump, making sure you don't get any air in it. Repeat the "pinch down" of the tube with it running.

I very seriously doubt the magnets have anything to do with the issue (and in thinking of how a mag drive pump works - can't come up with anyway it even could cause impeller rattle).

Note about the back pressure causing impeller rattle - when the flow restrictions are too high, the impeller can't rotate at the same speed as the driving magnetic field. The impeller ends up starting to move forward, but because of its slow speed due to the back pressure, it ends up "falling out" of its current magnetic field lobe. At that point it actually reverses direction until the next forward driving lobe starts moving it forward again. To envision what is going on, think of it like you have two permanent magnets, with one alternately being reversed in direction. This will alternately push and pull the 2nd magnet. This alternating motion is what causes the rattle you hear in those cases.

My Eheim 1048 is completely quiet, I need to touch it to know if it is running. It might be because of the system beeing 1/2" ID so the backpressure is very low.

If you try to run an Eheim 1060 with 1/4" or 3/8" tube I would be impressed if it didn't make a lot of noise...

My Eheim 1048 makes exactly that raddling sound if it runs out of water...

The sound byte you posted sounds like a buzzer!

My Ehiem 1250 made a crackle sound until the air came out, but nothing as noisy as the sound you posted.

If I pinch the tubing I can cause pump rattle. Back pressure issue as explained previously here.

Also, I epoxied the impellor to the shaft on my pump.

Jim

I superglued the impeller to the magnet and the rattle went away, I suspect it was because of back pressure as I've never had problems with getting the air out of the system.
The pump is very quiet now, you really have to put your ear next to the pump to hear it, a very low humming sound.

Don't glue the shaft to the impeller! Remove the shaft from the impeller/magnet assembly while applying the glue and don't insert it till the glue has cured.

I believe he means the cermaic shaft.
Sparx