Eheim 1250 makes a slight crackling noise?
 

Just installed a brand new Eheim 1250.

The pump makes a slight crackling noise :(

It is attached to T piece by a thread reducer (Part of a 3 tap filling system), and maybe this could be affecting things?

In a day or two I will try it with the original barb on, with just hosing.

Ideas?

Just for an idea (I have never owned an Eheim)

When my aquarium pumps do this and I have had aquarium pumps for... 10+ years now... it usually means the impeller is dirty and is causing the rotation to be thrown off. Therefore the sides of the impeller are striking the walls. Usually what I do to fix it, is completely remove the impeller and clean it and all the interior walls with a pipe cleaner.
The problem here, is the pump is starting out like this. I don't like it. I may have taken it back and exchanged it as another user may have not cared. The only positive note, once the bacteria and goo starts building up it may coat the outside of the moving parts and buffer the sound and workings. AND eventually that impeller may strike the surface and wear down and balance itself. (don't hold your breath)
While putting on the new fitting, do you think you may have bent part of the casing closer to the impeller?

Grungrefjaert sent me this link to solv my rattling Eheim trouble. It made wonders!
http://translate.google.com/translat...language_tools
Godd luck!
Mikael S.

I tryed it with stock barbs, in a sink (submerged) and the crackling sound was still detectable :(

I think it may be the impeller spinning slightly unevenly?

This isn't really pleasing.

EDIT: Took it apart completely, and it still makes the sound. Maybe the impellor is hitting something lightly as it spins? Sounds like it could be that.

I'm pretty sure it is the impeller. I think it is a little unbalanced.

I removed it and the ceramic shaft. I held the shaft between thumb and forefinger (held the ends), with the impeller on it and then spun the impeller. I could feel an unevenness and variation in the spin :(

The impeller does not move on it's shaft thingo like my 1048's, so I don't think the mod will do anything.

I think a replacement impeller is probably needed.

I suppose it comes down to whether the pump could be damaged, or it's pumping affected by this? I doubt it, and the noise is not audible above other noise unless close to the pump.

I took about 50 shite photos of what I think is the problem, and none of them was suitable.

So I used my photoshop skills to apply a filter to try to make the defect obvious.

The darker patch on the right side of the blue ring is a largish chip missing. I think it could be enough to unbalance the impeller.