Self Priming Pump Unable to Draw Water due to Strainer Full of External Debris, Exploring Possible Causes and Solutions


Client: Farm House on the outskirts of Ahmedabad, Gujarat.

Complain: Self Priming Pump unable to draw water



Lubi nameplate
Nameplate of pumps
Self Priming Pump
Lubi's Aqua Max I
Self Priming Pump



One of our clients had installed our Aqua Max 1 Pump at his farm house to draw water for various works.

One day their gardener noticed that the pump was not able to discharge water.  He informed our client about the same, who then called us up on our toll free helpline number to register a complaint. 


  • Customers can register a complaint by calling our toll-free number, after which they will receive a text message with information about the complaint as well as the contact details of our service engineer.
  • Our Engineer usually calls up to fix an appointment as per the electricity schedule of the area - as there are frequent power disruptions in some places. 

Our service engineer reached the site as per the pre-scheduled appointment.



Our service engineer reached the location and immediately began his inspections to verify the complaint and identify the root cause of the problem.


  • Power Supply: As always, our engineer first checked the pump’s power supply. After inspecting the connections, our engineer turned on the power supply. He noticed that the quantity of water being fetched by the pump was almost negligible. 
  • Leakages: After checking the power supply, our engineer moved on to check for any leakages - but he could not find any. 
  • Bypass Valve: Our engineer then had a look at the bypass valve to check if someone might have accidentally left it open.

Note: The bypass valve is left open only when the pump is not being used. Under normal circumstances (when the pump is working properly), it should always be closed or else it can drastically reduce the pressure.

Now that all the basic parameters had been checked, our technician separated the pump from the delivery (outlet) pipe to check if water was coming out, but it was not.


  • Non-Return Valve (NRV): Our Self Priming Pumps are pre-installed with a Non-Return-Valve (NRV). Our engineer decided to check the NRV. So, he removed the NRV from the pipe. He also separated the suction flange.


As soon as he opened it, he found that the strainer in the flange full of external debris, thereby preventing water to pass through it.


Self Priming Pump
Strainer Full Of External Debris



Our engineer cleaned the strainer thoroughly. He also cleaned the volute of the pump to ensure no debris was left behind.


Self Priming Pump
Cleaned Strainer


After he finished cleaning, he refitted the suction flange and NRV to the pipes. He made sure all the bolts and nuts were tightened properly. 

Once all fittings were in place, he switched on the power supply and found the pump working perfectly. 



  • Water Type: Self-priming pumps should always be used for "soft" water. The pump's lifespan can be shortened by hard water.
  • Rubber Flange: Make sure there is no cut in the rubber flange packing of the pump or else it can cause leakage. 
  • Non-Return Valve (NRV): The functioning of the NRV is crucial for the proper functioning of the pump. Do make sure that the NRV is installed properly. Regular inspections should also be done to check for leakages and proper spring tension.
  • Leakages or Presence of any debris anywhere in the pipeline can impact the flow of water.
  • Always maintain a cover over the pump to keep water and other particles from getting inside.



The following measures can ensure that your Self Priming Pump lasts longer with little or no downtime.


  • Always ensure your Self Priming Pumps get continuous (Single Phase) power supply of 180-230 V. 
  • The winding and insulation of the pump should be regularly checked using a megger meter
  • Always check the movement of fan (behind the pump) before switching on the pump. It should not be jammed or obstructed in any manner and should rotate clockwise. 
  • Any kind of leakage can impact the flow and pressure. It is advisable to check the nuts and bolts of the pipe, to ensure they are tightened properly.
  • Always fill the suction line with water before switching on your Self-Priming pump.
  • Cut the Rubber Flange packing properly before installing / operating the pump. 
  • Always run the pump at the duty point as declared by the company.


Final Words:

Always follow the guidelines provided by the dealer while buying or repairing the pump. 
You may also refer our user manual or call our toll-free number for any assistance.