Pump surge question

[Nordy-que]

In the midst of a pool refinishing startup. Lots of things have changed since there are new drain covers, jets, etc. I’m getting air in the system periodically that I can generally solve by lubing the pump filter cover o-ring. Since I’ve been messing with it more over the last few days and playing with valve settings again, I noticed that if I turn off the skimmer completely, or even a little too far, I get a ton of air in the system and the pump will surge.
I’ve got a 3 way Jandy valve for the spa drain and jets, wondering if that would be the culprit, but don’t understand why I’m getting more air in if I only have the main drain inlet on and nothing else. Ideas appreciated!

 

[Pool_Medic]

Check all your connections going to the pump, also check your filter.

 

[Nordy-que]

No air in system currently, but the question remains: if I turn off the skimmer, is it normal for the pump to surge?

 

[Pool_Medic]

If you’re choking off the water flow it makes perfect sense that the pump will surge.

 

[Nordy-que]

Thanks - I haven’t had a pool for long so still learning. I assumed, incorrectly I guess, that diverting all the water to one inlet would provide enough flow.

 

[Pool_Medic]

Are you certainly the main drain was fully primed? It sounds like it might not be, when I open pools up east. One line gets fully primed before we open a valve to then start priming another, the instant you move that valve the pump will lose prime and surge until themain drain is fully primed.

 

[Nordy-que]

I’m thinking now that I still have chunks of plaster and what the pool builder called cream in the drain line. I thought it had all broken loose but I had a basket full of the stuff again this morning.

 

[mas985]

Is your pool water level high enough? It needs to be at least half way up the skimmer opening.

 

[Nordy-que]

Yeah, it’s definitely high enough there.

 

[Nordy-que]

Replaced the jandy valve o rings on both inlet and pressure side. Zero air in the lines or pump housing now!