Vertical Immersion Pump Troubleshooting Guide

Zero Fluid Delivery

Air within Pump

Ensure pump is fully primed.

Insufficient Manometric Head

Requirements of system exceed that of pump. Check system losses,   against pump specification. Check pump impeller.

Reverse Operation

Check direction of rotation is correct

Impeller clogged or valve clogged

Remove obstruction

Reducing flow or none at all

Water liquid level in pit is too low. Pump is handling water with air

Increase liquid level in tank, or stop pump before reaching low level

Increase of Manometric Head

Pump is underspecified. Increase impeller diameter and motor size

Impeller or suction strainer clogged

Clear blockages

Motor Overloaded

Pump is operating at Lower Manometric head

Add backpressure

Speed is too high

Reduce pump speed

Mechanical Friction inside Pump

Check alignment. Replace bearings and bushings where required

Bearings Overheating

Insufficient Lubrication, deterioration of grease or no grease

Replace bearings, or regrease

Bearing Covers Overtightened

Remove cover and refit

Insufficient Cooling

Check pump operation at low level

Excess Grease

Remove Excess Grease

Vibration

Unbalanced Parts

Remove parts and check

Clogged Impeller

Unclog impeller

Impeller Worn

Replace impeller

Oblique Shaft

Replace Shaft

High Noise Level

Flow Rate too high / too low

End of curve operation. Adjust to Best Efficiency Point (BEP)

Water mixed with Air

Stop operation of pump at low water level or increase tank contents or   reduce operational speed

Pump is working in cavitation area

Correct system pressure, and pump speed