Model: ISG, IRG, IHG, ISW pipeline pumps
Ten causes of a pipeline pump that starts but gives no water or too little, from air in the casing to a worn wear ring, and how to fix each.
Not sure this pump fits your duty? Try the pump selector
| Cause | Fix |
|---|---|
| Air in the casing, pump not primed | Fill and vent again |
| Air leaking into the suction pipe or seal | Seal the joints; check the seal |
| Wrong direction of rotation | Swap two motor phases |
| Speed too low, supply voltage low | Check the supply |
| Impeller inlet or passages blocked | Open and clean |
| Foot valve blocked or leaking | Clean or repair it |
| Water level fallen, suction lift too high | Recheck the height; lower the pump |
| Wear ring and impeller worn | Replace the worn parts |
| Vortex at the inlet drawing air | Submerge the suction deeper; add a baffle |
| Discharge head higher than planned | Compare the real head with the curve |
If the pump gives water but not enough, measure the discharge pressure and compare it with the curve in the selection table. That tells you whether the problem is the pump or the system.
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