If your pump isn't drawing in liquid, commonly referred to as "taking suction," there are a few primary reasons why this might be happening. Addressing these common issues can help restore proper pump operation.
Common Reasons a Pump Fails to Take Suction
Based on operational insights, including the provided reference (04-May-2022), here are the main culprits:
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The pump is not primed: For many types of pumps, especially centrifugal pumps, the pump casing and the suction line must be completely filled with liquid before starting. If there is air in these areas, the pump impeller cannot create the necessary vacuum to lift or move the liquid.
- Solution: Re-prime the pump and verify that the suction line is full of liquid. Ensure all air is expelled from the system.
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There's an obstruction in the suction line: Anything blocking the flow of liquid into the pump can prevent it from taking suction. This could be debris, sediment, or even a closed valve in the suction piping.
- Solution: Inspect the line and remove any obstruction. Check screens, filters, foot valves, and the piping itself for blockages.
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The impeller is clogged: The impeller is the rotating component inside the pump that transfers energy to the liquid. If it becomes blocked with debris or foreign objects, it cannot effectively move the liquid, preventing suction.
- Solution: Inspect the impeller and remove the obstruction. This usually requires opening the pump casing, so follow safety procedures and consult the pump manual.
Understanding these potential issues and their straightforward solutions is key to troubleshooting a pump that isn't taking suction.
