I've attached a picture of my system. I want to understand how it works. I'm somewhat technical and should be able to catch on. I'm having some problems and want to understand what my PB is doing and why. We just replastered and he started it back up this week. It was running in service mode (Aqualink controller) continuously in order to work out the plaster dust and I'm brushing it daily. Time to change it back to Auto and I notice on the Aqualnk panel that it is on "Spa Drain". Weird I thought so I changed it to "Pool mode" and the spa began to drain. Shut everything down-- Jandy valves work but I think one of the toggle was wrong---set both toggle switches to ON1. Put in Pool Mode and turned on the filter. At first it seemed as if it would run--the pump primed--then the pump lost prime. Checked the skimmer and it was sucking in water faster than the pool could supply it. Now waiting for PB tech to come out---but I want to understand this so I know what is going on, now and in the future when it is out of warranty. Picture shows main set up--there is a secondary pump for a waterfall--it is all turned off. Thanks!