It's been some time since I've used the spa. We had friends over today and I put the thing in spa mode and noticed the level steadily going down.
I went and checked the Jandy valves and my return valves were rotated what I think is the right way.. but I was losing spa water like I was in "spa drain" mode.
The top valve is the return valve, it's half way to the neutral position (so the spa return is open and the pool return too?)
The bottom valve is turned far right, which opens the spa drain and blocks off the pool return.
This seems like the spa would drain given that "Spa drain" is in the full open position... but it also seems like it shouldn't be in spa drain mode at all as it would be returning the hot water to the pool and filtration system?