My sump pump is working but not pumping water out. I filled my bathtub with water and put the Pump in there to make sure it worked and water flowed freely and strong up throughout the attached pipes. It was all the way up to the the valve that I had with me in the bathroom. When I connected the pump back in the pit area there was one good suction but not emptying. I have a small area flooded in my basement but it is not getting worse or better. What else can I check?