Circulation pump Quiet One 3000 hiss

[bromion]

I just installed a Quiet One 3000 circulation pump in my new sump. It's overall very quiet, but about every minute or two it makes a very audible hissing sound for about 5 to 10 seconds. Is this normal?

 

[Blown 346]

I have three Quiet One pumps and they done hiss and never have. Is there air being sucked in somewhere?

 

[UCanDoIt]

Nope, not normal.

 

[bromion]

Time to call tech support. Thanks!