Why is 1 spa jet/eyeball connected to my pool return, spa keeps draining

[TroubledMike]

Hello,

First post on here and thank you for helping. Moved into house built 1985 combined in-ground Spa/Pool with spa elevated above pool. Spa draining to pool water level with pump off AND while in spa mode (suction/return only open to yellow spa lines) fairly quickly. Spa has 5 spa eyeballs/jets (no air is coming out of them, not sure if it's supposed to) and 4 of them clearly connected to spa return and 1 of them is clearly connected to the pool return. While in spa mode, I can feel the 1 spa jet draining water back into pool return line. No relevant check valves apparent to me in above ground plumbing pictured above. When I clog that jet with makeshift aluminum foil cap it no longer drains in spa mode.

1. Why is my pool return connected to 1 spa jet? Where might this connection happen? Is capping off the jet my best solution? Aluminum foil stops draining while in spa mode, pictured below.

2. Residual problem is that pool still slowly drains while pump is off and aluminum foil cap in place. I'm thinking next step is to replace diverter assembly in Jandy valves because maybe the hot tub is connecting to pool through there still?

3. What is that pink-circled blind end PVC pipe sticking out of the ground??

Any help is much appreciated and I am happy to answer any questions. Also, would love to know some troubleshooting/diagnostic testing to help narrow down problems more.

 

[ajw22]

Welcome to TFP.

You have very old grey Jandy diverter valves. Those are not the Neverlube black diverters. We recently discussed the gray Jandy valve in this thread...

Jandy Never Lube Leaks

I have the Jandy Never Lube Valves...and they have black knobs on the outside of the valve housing. I assume the idea is to turn the knob to add pool grease to the inside surfaces...without having to remove the 8 screws on the top and pull out the diverter. Never seemed to be a good idea to me...

www.troublefreepool.com

My guess is the Pool/Spa diverter on the return is not sealing perfectly and so when in spa mode the spa naturally will drain back to the pool water level.

Your pool return is connected to 1 spa jet to keep your spa water fresh and chlorinated and keep your spa spillover running when in POOL mode. There should be a check valve on that spa makeup line so that water does not backflow into the pool when the pump is off or in SPA mode.

Dunno about the pink capped pipe.