WalkerPools

I am having the same problem. I have an elevated spa that drains down to the level of the pool each night. On the return side are two jandy check valves, one as it exits the heater and one after the jandy valve used to switch from pool to spa return. Is it possible I need to replace both of them. I replaced one of them and the problem was not fixed so I switched check valve to the where the other check valve is located and the spa is still draining. Is there any other problem I could be having. Thank You. Adam