I stopped my pump to clean out my sand filter (and I expect is lost prime). I have now put the filter back together and restarted the pump but it has not yet been able to draw water. I have automation and it is ‘on’ – so it tries from time to time – but does not succeed in building enough pressure to get the water flowing again. Is there something I need to do to ‘reprime’ or reinitiate the pump? I tried putting water down the basket filter before the pump but it seems to just drain away.