Should there be sitting water in the crevice on top near the handle? We recently had a pool company come out and replace the multi-port valve and booster pump and have since been losing water. I can only imagine the valve top isn't seated correctly onto the gasket or there is a defect in its construction. We are sitting some sitting water on top though and wondered if that was normal.
Beyond that, I can only assume there might be leaks in the return lines since we hadn't ran a booster pump in some time. The water loss seems to only really occur with the pump on, so I imagine one of these two is the culprit.