Failure Possible Causes Methods 1.Pump not suck water, both pointers of manometer and vacuometter severly jump. a:Water input the water pump is not enoughb:Air leakage on water input pipes and instruments a:Input more water into water pumpb:Tighten and block the air leakage parts 2.Pump not suck water, high vacuum shown on vacuometer a:Bottom valve not opened or blocked upb:Too large resistance of the suction pipelinec:too high suction height a:adjust or replace bottom valveb:clean or replace water input pipesc:reduce water input height 3.No water out through pressure is shown on manometer a:too large resistance on outlet pipelineb:Uncorrect rotating directionc:Impeller blocked up d:Insufficient