| Possible causes | Recommended action |
| Gland packing is damaged. | Replacing gland packing |
| Mechanical seal is damaged. | Replacing mechanical seal |
| Boost pressure is excessive. | Review the plan |
Rotating, but water does not come out. Discharge quantity is not enogh to specified capacity.
Over load (Overcurrent) occurs.
Electric motor does not work well with noise.
Water comes out at first, but it doesn't come out soon.