| Malfunctions | Possible Reasons | Eliminating Methods |
| 1. Pump doesn’t absorb water. And the finger of pressure gage and vacuum gage jumps tempestuously. | 1. Filled water isn’t enough. 2. Leakage on pipeline or instrument. 3. Vacuum suction device damages or does not work. 4. Priming check valve does not work. | 1. Fill water in the pump again. 2. Screw down and block the leakage 3. Adjust or repair. 4. Repair priming check valve. |
| 2. Pump doesn’t absorb water. And vacuum gage points at high vacuum degree. | 1. Bottom valve does not open or blocked. 2. Much resistance in suction hose. 3. Suction height is too high. | 1. Revise or replace bottom valve. 2. Clean or replace suction hose. 3. Reduce the suction height. |
| 3. No water comes out from pump but there is pressure on the pressure gauge. | 1. Much resistance in outlet pipeline. 2. Rotation direction of is not right. 3. Impeller is blocked. 4. Rotate speed isn’t enough. | 1. Check or shorten outlet pipe. 2. Correct rotation direction. 3. Clean impeller. 4. Increase rotate speed. |
| 4. Voice in the pump is abnormal and no water enters into the pump. | 1. Much resistance in suction hose. 2. Suction height is too high. 3. Air enters the suction hose. 4. Cavitations erosion occurs due to larger flow rate. | 1. Clean suction hose and bottom valve. 2. Reduce the suction height. 3. Block the leakage. 4. Turn down outlet valve and reduce flow rate. |
| 5. Bearing is overheating. | 1. No lubricant in bearing. 2. Cooling pipe is blocked. 3. Pump axis and power input shaft are not in the same center line. | 1. Fill up lubricant. 2. Check cooling pipe. 3. Proof the concentricity. |
| 6. Pump doesn’t absorb water and vacuum gauge does not work. | 1. Leakage on suction hose. 2. Primer valve can’t open. 3. Primer check valve does not work. 4. Belt pulley device fails. | 1. Check and block stream leakage. 2. Check and repair primer valve. 3. Check and repair check valve 4. Check and repair it. |
| 7. There is leakage on shaft gland. | Filling of shaft gland is frayed. | Fill in proper filling. |
