| Possible causes | Recommended action |
| Pump operating in reverse rotation. | Change the rotating direction to the appropriate way. |
| Pump is clogged. | Disassemble and remove foreign objects. |
| Resonance in piping. | Improving piping |
| Looseness of tightening bolts | Tighten the bolts of each part sufficiently. |
Over load (Overcurrent) occurs.
Pump works at first, but it stops soon.