Why is pump draining down hours after turning off

[yashrg]

For several days now, I have been noticing issues with the pump starting up in the morning because it does not successfully prime on its own in the morning.
Even when I do prime it and let it run the schedule, after it turns off, the pump looks like it has water. However, by next morning it would be empty again. Tried many potential fixes, replaced rubber gasket on lid, checked valves for leak, nothing seems to be helping.
So I set up a timelapse during the daytime to see what happens with the pump off. I was expecting to see the water level maybe gradually go down if there was some leak or air gap. But what I saw was that at one point the pump suddenly and quickly empties out.
I am trying to share the timelapse video via iCloud, hopefully that is allowed on this forum.
I have also attached a photo of the equipment. The spa return in the photo is completely off, but it does the same thing even when return is in the center.

iCloud Photos - Apple iCloud

View, organize, and share photos and videos with iCloud Photos on the web. Changes will sync across your devices with iCloud.

share.icloud.com

 

[ajw22]

Welcome to TFP.

Post your video on YouTube and post a link to it here. Make sure you mark the video PUBLIC on YouTube.

 

[yashrg]

Welcome to TFP.

Post your video on YouTube and post a link to it here. Make sure you mark the video PUBLIC on YouTube.

here’s a YouTube link.

 

[Texas Splash]

Air must be entering the system from somewhere. You have a lot of connections at the pad. You['ll have to be extremely thorough and check each one. Doesn't take much to break that air-tight seal and allow air in.

 

[Jimrahbe]

Yas,

I suspect that the delay is cause by your filter draining back into the pool, which then causes your pump to drain down. A very small leak causing things to slowly happen.

I would clean or replace the filter air vent valve.

Thanks,

Jim R.

 

[yashrg]

Thanks. I will add the filter air vent on the list of things to check next.
With regards to the other various connections, pool guy looked at the check valves using some soap foam to see if any air was being pulled in. Neither of us saw anything happening. Is there any other technique that is worth trying?

 

[1poolman1]

For several days now, I have been noticing issues with the pump starting up in the morning because it does not successfully prime on its own in the morning.
Even when I do prime it and let it run the schedule, after it turns off, the pump looks like it has water. However, by next morning it would be empty again. Tried many potential fixes, replaced rubber gasket on lid, checked valves for leak, nothing seems to be helping.
So I set up a timelapse during the daytime to see what happens with the pump off. I was expecting to see the water level maybe gradually go down if there was some leak or air gap. But what I saw was that at one point the pump suddenly and quickly empties out.
I am trying to share the timelapse video via iCloud, hopefully that is allowed on this forum.
I have also attached a photo of the equipment. The spa return in the photo is completely off, but it does the same thing even when return is in the center.

iCloud Photos - Apple iCloud

View, organize, and share photos and videos with iCloud Photos on the web. Changes will sync across your devices with iCloud.

share.icloud.com

Stem and lid O rings on any of the 6 valves in the picture, including the check valves, and any others that may not be seen, can allow air in which will allow water to slowly drain. Air can get in through leaks that are too small for water to get out off.