Float operation obstructed or restrained. Add water to sump and observe turn-on. Readjust control floats or weights. Float rod bent or obstructed by debris. Observe and check float or weight freedom. Readjust control floats or weights. Diaphragm control skirt lost trapped air. Manually override control to check pump operations, if override is provided by manufacturer. . Lift pump above fluid level in sump. Then holding pump straight and vertical, place pump back into sump to re-trap air in control skirt. Compression fittings retaining pressure tube between control skirt and control are loose. Examine and observe. Tighten fittings. Then lift pump above fluid level in sump and holding pump straight and vertical, place pump back into sump to re-trap air in control skirt. Pump not positioned firmly on bottom of sump. Disconnect power and check pump for stability. Readjust discharge piping and pump.