No water or few water out from pump: 1,Check the oulet pipe ,inlet pipe whether there is block in the pump ,remove the block. 2,Check the rotate direction of the motor,and is there open phase/default phase problem,adjust the direction of motor,fix electric wire. 3,Check the suction pipe,see if there is location leak air,tighten the seal surface,exhaust air. 4,The pump is not filled with liquid,there is still air inside,open the air evacuation valve to fill the liquid of the pump. 5,Inlet supply is lack of liquid,the distance from liquid surface to pump is too long,the suction head lift will be declined if the pipe is too long,we usually design the suction pipe with sortest distance from liquid surface to pipe inlet.so,stop the pump system,exam and adjust the pipe. 6,The resistance of pipe net is very big,and the type of pump chosen is not fit.do not use too many pipe bends,and choose a type of pump fits the system. The pump flow is very low: 1,Check the pump and pump system as...