How To Prime a Pool Pump

This guide will walk you through priming a pool pump. When a pool pump is priming, it is purging the plumbing system of air to create a vacuum effect to pull water from the pool, push it through the filter and back through the return line. An inground pool pump should be able to prime itself under normal circumstances. But if you have had to de-pressurize the system for maintenance, i,e, pump motor replacement, cartridge cleaning,  manual priming is helpful to give your pump a head start for priming.

1. Turn off power to your pool pump at the circuit breaker.

2. Make sure your pool’s water level is at least halfway up the skimmer face. Also, remove debris from the skimmer’s strainer basket.

3. A suction side diverter valve allows you to select whether the pump will pull from either the skimmer, main drain or both. Use the valve to close either the main drain or skimmer line to that the pump is only pulling from the other line. We do this to concentrate pump’s suction, to increase the efficiency of the priming cycle.

4. Open your filter’s air relief valve to allow air to escape as we manually prime the pump. You may hear the noticeable hiss of air passing through the valve when you open it, and after the pump is turned on, this is normal. Sand filters may not have an air relief valve, but rather an internal air relief tube which releases pressure automatically.

5. Remove your pump’s strainer lid. To open up the strainer box, 1-turn the two knobs on top of the strainer lid counter-clockwise and 2- swivel the knobs down away from the lid. Note: Some strainer lids screw on instead of having knobs. In these cases twist the lid counter-clockwise to remove the lid off the top of the strainer box.

6. Remove any debris from your pump ’s strainer basket to improve the pump’s suction during the priming process.

7. Fill your pump’s strainer with a hose or bucket until the water sits above the pump strainer’s intake port. Filling to this point ensure the suction pipe is purged of air.

8. Reattach the pump’s strainer lid. You may want to add a new coat of lube to the pump lid’s o-ring to increase the o-ring’s longevity and prevent any future sucking air leaks.

9. Make certain that any valves on the main return line are open. This will allow the pool pump to discharge water to the pool. If this is not open, excessive water pressure that builds up during pump operation may damage parts of the pumping system and may be dangerous.

10. Turn on the pool pump breaker, then turn on the pump.

11. Keep an eye on the pump’s strainer lid to ensure water is flowing. After the initial water, we used to prime the pump flushes through the system, water should begin to freely flow and fill the pump’s strainer basket. If after a minute, water still has not begun to fill your pump, restart from step one in this guide, and if the problem persists, read this guide: How To Determine Why a Pool Pump Won't Prime.

12. The air relief valve should still be open. As the pressure builds, air will be released through the relief valve. When water starts to spray out of the valve, turn the valve clockwise to close it.

13. After the pump has primed itself, reset the suction side diverter to pull from both the main drain and the skimmer.

14. If water isn't flowing freely in 30-60 seconds, repeat steps: turn off the pump, bleed off the pressure, reopen the strainer, refill the strainer, and close the lid. Then turn on the pump. You may have to repeat these steps several times to purge the air from the line.

15. When water is flowing through the pool skimmer lines, slowly open the main drain line at the diverter valve. Open the relief valve to allow air in the main drain line to escape. Again water should flow freely in 30-60 seconds. Close the relief valve. If you don't see pressure building on the pressure gauge and a full strainer box, repeat steps 1 -10.

16. If, after repeated attempts, you cannot prime the system successfully, your system has a major leak or blockage. This problem must be resolved before you can prime the swimming pool system.

17. As stated earlier, if after a minute or attempting to prime water still has not begun to fill your pump, or after your reset the suction diverter valve the pump loses prime, restart from step one in this guide, and if the problem persists, read this guide: How to Determine and Correct Air Leaks.

If you have any other questions about pool and spa products please do let us know - we are here to help! 

Leave a comment