Plumbing conundrum

[Drew80]

I just had a brand new pool built, and I'm confused about how they plumbed it. On the suction side, there's a 3-way valve that controls pool/spa with a 2-way valve on the skimmer and a 2-way on the pool drain. That makes sense to me. On the pressure side, there's a 3-way for the pool/spa with a 2-way on the spa jets and a 2-way on the bubblers. The spa jets and bubblers are on the same return. The picture below is my return plumbing. Left to right is pool, bubblers, spa.

https://www.dropbox.com/s/hzailt3b1wic1jk/Screen%20Shot%202018-04-06%20at%2011.06.09%20AM.png?dl=0

I'm not sure why they put the bubblers and spa jets on the same return. Maybe it's so I can run the spillover and bubblers at the same time, which makes for nice water noise. But I'm confused about a few things:

1. If I have it in spillover mode and I open the bubbler valve, pressure on the pump goes UP instead of down. How is that possible? I'm opening up two more pipes, so resistance should drop - simple physics.

2. If I open both spa and bubbler valves, the bubblers get no pressure. As in zero - no water flow at all. It all goes to the spa. I have 8 spa jets and 2 bubblers, so I would expect the bubblers to get 20% of the water flow. To get the bubblers to activate, I have to slightly close the spa valve - 1 or 2 steps. When I do that, the bubblers get a little bit of flow but the spa jets stop completely. If I close the spa valve all the way, the bubblers turn into fountains - that part makes sense. But why am I not seeing a proportional amount of water flow to the spa jets if I close it partially? And why am I not seeing 20% of the water flow going to the bubblers when they're both open?

Similarly on the pool side, if I open the pool drain and skimmer at the same time, pressure goes up and the pump somehow sucks in air. Am I somehow creating backflow on the return valves?

 

[kadavis]

When you activate the spa and the two valves turn are just the spa jets working. In the picture the pipe labeled pool return should've been the spa jets and vice versa. So either its labeled wrong or they crossed the two pipes into the valve

 

[Drew80]

They're not labeled wrong - they screwed it up. The valves in the picture are in spa mode. The 3-way valve is set to the spa side, the spa jet valve is open, and the bubbler valve is closed. As I said, the bubblers and spa jets are on the same side of the 3-way.

I'm not confused about the valves themselves. I'm confused as to why opening both valves on the right side doesn't distribute the water between the spa jets and bubblers. If they are both open, it sends all the water to the spa jets, none to the bubblers, and the pressure on the pump actually goes up. I have to close the spa jet valve a little to get any water to go to the bubblers.

It's like the water is rushing past the T that goes to the bubblers and pushing everything to the spa jets, and maybe even sucking some of the water backward from the bubblers. Maybe I need check valves?

 

[kadavis]

Well I do no water likes the path of least resistance

 

[kadavis]

The only answer I can give is the spa jets line and pool return line needs to be flip flopped. I take it the bubblers are in the pool and if so then everytime you want to use spa you have to make sure the bubbler valve is closed. If the lines are reversed then the bubblers could be controlled by closing pool return valve or by using smaller return openings on the pool returns