Hi there. Our freeze guard kicked on last night and one of our pumps was so loud we could hear it inside the house. We have determined that it is the dedicated pump for the deck jets (there are 4) - this pump does not go through the filter. I have cleaned the basket, checked the impeller for debris (didn’t seem to be any), and cleaned/relubricated the skimmer lid o-ring. When the skimmer is open, the water is at the top, even slightly continuously spilling over (there is no valve on the suction, other than a flapper valve, so I can’t turn off the suction). As a matter of fact, I’m not even sure where the water is pulled from for the deck jets (we have 2 floor drains and 2 skimmers). Once the pump is turned on, it immediately loses prime and is incredibly loud. It’s clearly sucking air. I am getting ready to check for air leaks. I just want to make sure I’m not missing something before I get back into it. Should I be looking for a clog somewhere? We did have a lot of leaves & debris in the pool. As we have two drains, shutting the drain suction off should stop the water from spilling from the open skimmer basket, correct? (It didn’t). Could it be caused by a bad spring check valve (I don’t understand how that could let in air, though). Could there be another source for that pump to draw from (skimmer, outlet on pool wall, etc.)? Thanks in advance. I just wanted to see if anyone else has experienced this. It’s pretty cold here right now, so the less time I spend outside working on plumbing, the better 
The attached pic is the plumbing for that pump only. The longer straight pipe to the right of the pump and suction is unrelated (waste water).
The attached pic is the plumbing for that pump only. The longer straight pipe to the right of the pump and suction is unrelated (waste water).
