| Possible causes | Recommended action |
| Bearing is damaged. | Replacing bearing |
| Excessive discharge quantity. | Adjust the water volume to the specified level with discharge valve. |
| Impeller is clogged. | Remove the foreign objects from the pipe. |
| Rotate in the opposite direction. | Follow the arrows to correct the wiring. |
| No-discharge operation for a long time. | Stop no-discharge operation. |
| Roatating part contacted.Or shaft is bent. | Repair at a specialized factory. |
| Cavitation is being generated. | Consult an expert. |
| Resonance in pipes. | Improving piping. |
Rotating, but water does not come out. Discharge quantity is not enogh to specified capacity.
Over load (Overcurrent) occurs.
Excessive water leakage from stuffing box
Electric motor does not work well with noise.
Water comes out at first, but it doesn't come out soon.