Our geothermal heat pump for our pool uses a pond in our back yard. It is a community pond and they do a good job of circulating the water and maint. to keep the algae and muck down. Our inlet has a large (huge) filter on it so we don't draw in any debris. Still - twice now, I have 'lost prime' as a leaf or weed has lodged itself into the check valve near the pump that prevents the water from flowing back into the pond (about 30 feet in length but only 6 foot drop). My current fear is that the pump has burned out when trying to restart the next day with no fluid. I will be testing the pump here shortly. Regardless of the pump status - I still need to solve this 'issue' of 'losing prime'. Looking for any suggestions to help here. I read about including a 'fluid check' of some source that will prevent the pump from running if there were no water source. Not sure how that would work - but it's one idea. Additional Info: The heater will only kick on when the pool pump is on. Currently, the pool pump runs from 6am to 6pm.