6105 making "humming" noise

[reefernutz]

I just got 2 new 6105s and one of them is making a humming noise. If you are standing in front of the tank you can hear it ramping up and down (it's an in-wall tank and the pump is on the back wall). Any ideas why it's doing this?

 

[rvitko]

The only moving part is the propeller so that is the usual culprit but causes can include.

1) Pump is touching a side wall or cord is reverberating off of the edge of the tank.

2) Front cover is not completely secure, check the gap for evenness to be sure it is fully seated.

3) The drive unit has a blemish or some foreign object is inside.

In general new pumps are louder, a couple of weeks of wear does reduce noise as the part seat.