Learning about pool pipes

[toggi]

Hi.
I am trying to troubleshoot an issue I am having with my SPA slowly draining into the pool, but I am also just trying to learn more about the purpose of the different pipes connected to my pool.

I believe the SPA draining might be caused by the valve handle on the return line pointing in a 2 o'clock position (circled in red). My understanding is that in it's current position I am returning water to both the pool and the SPA. If I want to operate in SPA only mode, should the valve handle point in a 12 o'clock position towards the wall? My understanding is that this would turn off the pool return line and only return water to the SPA?

I plan to take pictures before turning these dials to be able to find back to the original configuration, but before I start, are there ways to seriously damage the piping if these valves are temporarily turned in the wrong directions?

Thanks!

 

[Ahultin]

If the spa is draining into the pool with the valves as shown, it is likely that the flapper in the check valve (just to the left of the one you are referring to ) is bad