What is a Self-Priming Pump? 

 A Self-Priming Pump - What is it?

A self-priming pump is designed to increase the water pressure in your home and garden by pumping enough air to suck water through the rotation of the impeller, prompting the pump to function. A self-priming pump, unlike other centrifugal pumps, does not need a gravity feed of water. Click here to see Recommended Self-Priming Pumps.

Self priming pump

How does a Self-Priming Pump work?

A self-priming pump is designed with an external casing (pump body) that is filled with water, causing the impeller to rotate and form a low-pressure zone, creating a partial vacuum. The partial vacuum removes the air from the suction line and pulls the water up. After the pump mixes the air and water, the air is separated from the water and released from the casing.

Most self priming pumps, especially in the DAB range, can suck water up to 8m below the ground. Instead of waiting for pressure from a gravity feed, the pump is able to suck the water up (which takes a minute and a half on average) before the pump has water from the source.

Where do you install a Self-Priming Pump?

A self-priming pump can either be installed below the water level in a well point system, or above the water level if you already have a rainwater tank installed below the ground.

If installed below the water level, gravity and air pressure ensures that the pump is constantly filled with enough liquid and no air enters the pump or suction line.

If installed above the water level (rainwater tank), air in the suction line must be evacuated or displaced before the pump can discharge the water, as pumps are optimised to move a particular liquid.

Benefits of using a Self-Priming Pump

The main benefits of using a self-priming pump:

  • Little maintenance is required as the pump automatically removes air and continues to operate
  • Designed to handle a variety of fluids, high-consistency materials, slurries, corrosive fluids and solids up to 8cm
  • Safer and easier to access, operate and maintain if installed above the water source

Disadvantages of using a Self-Priming Pump

The main disadvantage of using a self-priming pump:

  • The ability to generate a low pressure zone is reduced due to wear-and-tear and from debris collected from solids on the impeller itself

Recommended Self-Priming Pumps

LEO AJM75S Self-Priming Jet Pump (0.75kW, 1.0hp, 220V)
LEO AJM75S Self-Priming Jet Pump (0.75kW, 1.0hp, 220V)


Dab jet self priming pump

DAB JET 112M Self-Priming Centrifugal Pump (1kW, 220V)

Do you recommend using a Self-Priming Pump?

Definitely. Self-priming pumps are safe, hassle-free and easy to maintain. If you need to increase the water pressure in your home and your water is situated below the ground, a self-priming pump is the answer.


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