why is water coming back up through the skimmer?

[jroddvette]

i have an above ground pool with a doughboy skimmer, 1.5hp proline pump and a sand filter with a mulitport valve. yesterday, i backwashed the filter until the sight glass was clear then rinsed for 45 seconds, then ran the pump for about 8 hours. the pressure didn't climb at all during this time, but when i turned the pump off water came back up out of the skimmer. so much water that the lid was pushed off the skimmer. does anyone know what would cause this to happen?
thanks, Jared

 

[JohnT]

Welcome to TFP

It sounds like your pump failed to prime, which would be unusual in an above ground pool. Is the pump above the pool water level? The water flowing back through the skimmer is a result of air being compressed in the filter. When the pump shuts off, the air expands and forces water out of the filter through the skimmer.

 

[jroddvette]

no the pump and filter are below the water level. is there any way to "purge" the air?

 

[JasonLion]

You indeed need to purge the air from the filter. The way you do that varies depending on the model of filter. There is often an air vent on the top of the filter that you open to let the air out.

 

[jroddvette]

i don't see a vent, but i'll post a pic later when i get home.

 

[syph424]

jroddvette:

I had similar problems with my inground pump when starting it up this year... I had a couple of small leaks that were keeping the pump from reaching full prime.

After fixing those, I cracked open the lid on my pump's filter basket to purge the air from the system. That seemed to do it for me, haven't had any issues since.

Good luck!