1. Pump does not prime
Passible cause
- Suction lift too great.
- Insufficient water at suction inlet. Suction inlet or strainer blocked. Suction line not air tight. Suction hose collapsed.
- Non return valve ball not seating.
- Mechanical seal/packing drawing air into pump.
2. Not enough liquid
Passible cause
- Incorrect engine speed. Discharge head too high. Suction lift too great.
- Suction inlet or strainer blocked.
- Suction line not air tight.
- Suction hose collapsed.
- Mechanical seal drawing air into pump. Obstruction in pump casing/impeller. Impeller excessively worn.
- Delivery hose punctured or blocked.
3. Pump ceases to deliver liquid after a time
Passible cause
- Suction lift too great.
- Insufficient water at suction inlet.
- Suction inlet or strainer blocked.
- Suction hose collapsed.
- Excessive air leak in suction line.