I recently had an issue with my pump not holding prime. Worked fine one day and the next...boom - wasn't holding prime! Checked the pump cover seal and it looked fine. Next, I took the lid off of the skimmers and found water gushing through one of them while the other was fine. Turned off the valve to the "gushing" skimmer and the pump began to hold prime. The culprit? A cracked skimmer weir on the "gushing" skimmer. Replaced the weir, turned the valve back on and problem solved. Just thought I would post this in case anyone else wakes up to this situation and as a reminder to make a few simple checks before making a service call.