Reduced pump performance is a common complaint. Discover the root causes and how to restore full pump capacity.
Low flow or pressure from a submersible pump can have several causes:
Worn Impeller
Over time, impellers wear due to abrasive particles. Worn impellers reduce efficiency significantly. Inspect and replace if clearances exceed manufacturer specs.
Air Lock
Air trapped in the pump casing prevents normal operation. Prime the pump by tilting it to release trapped air.
Clogged Strainer/Filter
A blocked inlet strainer restricts flow. Clean or replace the strainer regularly.
Discharge Pipe Too Small or Too Long
Friction losses in undersized or excessively long discharge pipes reduce effective flow. Recalculate pipe sizing.
Pump Operating Outside Duty Point
If the system head is higher than the pump's design point, flow will be reduced. Check the pump curve against your system curve.
Partially Closed Valve
Check all valves in the discharge line are fully open.
Voltage Drop
Low voltage reduces motor speed (for induction motors), directly reducing pump output.