I'm helping a friend with his pool that he is having issues with. When the pump is priming there is never enough suction/flow. He has a skimmer, three return jets, and two floor drains. The skimmer and drains each have a valve. If he opens the valve for the floor drain he loses flow almost immediately. This is a Jandy VS pump that is self priming. The pump may be having issues. It's a year old but doesn't sound very strong. Any help would be appreciated. I'm curious why opening the floor drain valve loses all water flow as well. This is my first time encountering a pool with floor drains. Also, the skimmer had two holes with the back one blocked. It's always been like that so could be normal.