A pumping system including a fluid inlet line and a primary pump for the fluid. The primary pump includes an impeller in an impeller chamber, with the impeller chamber adapted to receive fluid from the inlet line. A suction chamber is above the impeller chamber, with a throttle opening between the impeller chamber and the suction chamber. A priming pump is adapted to draw fluid through the throttle opening into the suction chamber. A fluid path is provided around the impeller chamber and between the inlet line and the suction chamber, with the fluid path having a larger area than the throttle opening and including a float restrictor.