beep sound in single controller

[7thheaven]

Hi....
I am using two 6110 models (6100+single controller)
Sometimes One of my single controller make warning noise.
About 10 seconds later,noise is gone....

I have experience this problem already twice...

I know that the sound are made when the pump is located
above surface of the water level. Is it correct? but Now my
pump is under the surface of water about 4inches.....



I don't know why.... and am worried about that...

 

[7thheaven]

The answer is here?

http://reefcentral.com/forums/showthread.php?s=&threadid=432647&highlight=sound

 

[rvitko]

Yes, their is no alarm in the controller- it is in the blue driver box and means the pump is dirty or has air in it.