This is our maiden voyage with our 2011 Prowler fifth wheel. We are at a camp site with electric hook up only. We filled the tanks and set up. However the low point drains were open and we lost a lot of water. The monitor said we had 1/3 left and I could hear the pump going and water would sputter out but never a stream. Now the monitor reads empty. Are the tanks just too low for it to pump? I purchased this from a reputable dealer but it hasn't been used since it's been winterized. I shut the pump off because I didn't want to damage it