Can you post a picture of the equipment pad?
tried, site will not let me.
spa pics from my facebook page.
https://www.facebook.com/photo.php?fbid=1390949767611731&set=pcb.1390950040945037&type=3&theater
Turn the outside valve 90 degrees clockwise to shut off line marked spa. With that line open spa will drain back to pool
we have replaced the check valve, don't know how old the spring is, that was my next move, find a replacement spring.Then its the check valve on the end. Unscrew cap off, should be a spring and a disc with a rubber seal. Usually have to replace disc, sometimes spring to.V20-068 Val-Pak Products
i picked up a new spring today will see if that helps.They make a 1lb and a 3lb spring might try the 3lb.Ortega (Purex) Check Valve Spring, SS 3Lb., 072524