Sump Pump Sucking Noise - After Cycle Stops

[mattdwright]

Hello,
Need some help on this one please.
New 1 HP Wayne sump pump and "quiet" check valve installed a couple of weeks ago. It runs great. However, after it cycles, there is a sucking/slurping noise almost like a vacuum has been created and fails. It lasts a second or two but is annoying and loud- can hear it upstairs. It's not the water coming back down from the check valve- I hear that as well, not a big deal. Do I need to add an AAV valve or something? Too much HP for the pit? It's a new pit, clean.
I have had 2 plumbers look at it and neither can tell what is happening. Hours online looking without a path to resolution. I am stuck!
I loaded a video of it I took of the end of the cycle> https://drive.google.com/file/d/1VA9Bcs5yJcmQf87Or3hXuEPLnvPkwBD2/view?usp=sharing

Any ideas or suggesstions would be greatly greatly appreciated!
-Matt

 

[Twowaxhack]

I think it’s pumping down too low. Like you didn’t make the pit deep enough.

Adjust it so it only pumps half the water out and see if it slurps.

 

[Jeff Handy]

Video is too short, does not make sense.

 

[Twowaxhack]

Sounds like me when I get to the bottom of my beer.

 

[Jeff Handy]

Watched it again, yes it appears to be pumping too low, sucking air.

But it would help to make a longer video.
Fill the sump pit from a garden hose.

Show the entire pump cycle, including at least five seconds before it starts and five seconds after it finishes.

Also, the check valve should be about three feet higher up on the discharge pipe.

Having it down in the pit leaves too much water above it, to slam down after a cycle ends.

 

[mattdwright]

Thank you all. I will repost a longer video.