How To Prime a Pool Pump


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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.

Things You'll Need


Step by Step


Step 1

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

Step 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.

Step 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.

Step 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.

Step 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.

Step 6

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

Step 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.

Step 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.

Step 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.

Step 10

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

Step 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

Step 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.

Step 13

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

Step 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.

Step 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.

Step 15

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.

Step 16

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 Why a Pool Pump Won't Prime and How to Identify and Correct Air Leaks 



(1 to 40 of 143)

 Posted: 5/27/2022 

What setting should the pump be on when priming? We just finished vacuuming and want to backwash but need to prime the pump to get it going again. Some things I've read say to set the pump on "recirculate" but wanted to make sure because we still need to backwash the filter. Thank you

InyoPools Product Specialist  Posted: 5/27/2022 

The pump should be able to prime regardless of the filter's multiport valve setting. The valve should only be turned while the pump is off and water is not actively flowing through the system. filter valve can be placed to any setting, and the 

 Posted: 4/10/2022 

I made a short hose with two female connections and attach it to the garden hose purge line on the discharge side, then turn on the water. Much easier to prime than taking off the lid, and then reattaching before starting,

InyoPools Product Specialist  Posted: 4/14/2022 

That's a unique solution to the priming issue. Thank you for sharing.

 Posted: 2/16/2021 

I have a new Hayward Tri-Star pump W3SP3202VSP which I bought from you. The default self-priming time is 8 minutes, but that seems unusually long to me. What amount of time do you recommend? How do you know what is long enough?

InyoPools Product Specialist  Posted: 2/16/2021 

It shouldn't take any longer than a couple of minutes to prime. It sounds like you may have an air leak causing the pump to take longer to prime or you may need to adjust the priming speed. You can see how to correct any air leak using this guide: How to Identify and Correct Air Leaks.

 Posted: 9/18/2020 

How long should it take for the pump to prime? Mine takes 30-40 sec.

InyoPools Product Specialist  Posted: 9/23/2020 

That is about right. You don't want it to run longer than a couple of minutes without water as parts start to overheat due to friction.

 Posted: 1/12/2019 

Hi! I'm looking for a cover for my filter system, it's broken and I'm looking to replace a new one, but I can't find a similar one. can you help me!

InyoPools Product Specialist  Posted: 1/14/2019 

Hello Lyly - We'd be glad to assist you. What is the make and model of your filter?

 Posted: 1/8/2019 

Hy, I did what you says but my pump still not priming. I tryed to shut off all valvs and that put the bucket of water into the pump and when I´m gonna to put the lid back on, the water level comes down again. And my pump again spin impeller without water (not priming)

InyoPools Product Specialist  Posted: 1/10/2019 

Hello Sven - You may have a significant suction side air leak if you are unable to keep the pool pump primed. Check out our guide titled "How To Identify and Correct Air Leaks".

 Posted: 8/8/2018 

Hello Ron - the PSI is going to vary greatly from pool to pool. The "clean" pressure of the filter should be noted after installing a new filter or replacement cartridge.

 Posted: 7/4/2018 

What is the "normal" operating pressure in a clean cartridge type filter?

Anonymous  Posted: 6/6/2018 

I can't find a diverter valve anywhere!

 Posted: 5/9/2018 

Hello Phil - The water level dropping below the skimmer line is usually a sign that the water level is too low to begin with. Try adding a couple of inches of water to the pool. The pool water level should be half way up the skimmer opening.

 Posted: 5/9/2018 

Ok, so I have had my pool for a year (second season) recently my water level is dropping below the skimmer when the pump is running, It was working fine 2 days ago but for some reason it all of sudden started to drop. Any Ideas why?

Anonymous  Posted: 8/30/2017 

Thank you. Worked like a charm. Just had to add water.

InyoPools Product Specialist  Posted: 7/31/2017 

Dave - It sounds like you have a significant suction air leak on the suction side of your pool's pump. See our guide on "How to Identify and Correct Air Leaks". Also, if you have an old pool, try digging down to the bottom of the input pipe that carries water into the front of your pump. Sometimes the elbow connecting to the horizontal pipe from your pool wears out and starts to leak.

Anonymous  Posted: 7/29/2017 

Thank you! This was extremely helpful and easy to follow the step by step instructions. My husband is out of the country and I was worried my pump would burn up or I'd have to turn it off and my pool would become a green mess. Very helpful!!!

 Posted: 7/29/2017 

So my pump only fills above the return opening I side the basket. I can't get the level to rise to the lid. I have tried to shut off the drain valve, leaving only the return from the pool open. I opened the pressure relief valve but no change in levels. The level inside my pool is where it needs to be.

 Posted: 7/28/2017 

Thank you so much!!! I got it running after four attempts. Thank you!!!

 Posted: 6/19/2017 

Blane - When you bought your new cartridge last year, did you have the same problem right away or did it build up over time? If it worked for a while, you made have invisible gunk like oils or sunscreen lotion building up in the flow of the cartridge that is hard to wash out. Try cleaning your cartridge with something like TSP get the gunk out of the folds.

 Posted: 6/19/2017 

Hello, when I do not have the cartridge in the Filter, the flow is great. as soon as I put the Cartridge in, I have good flow for about 40 seconds, then it is really weak. I thought the Cartridge was bad, bought a new one, and have the same issue. this is frustrating. the Filter is a Hayward c550, and I purchased it last year.

InyoPools Product Specialist  Posted: 5/30/2017 

MrRice - It sounds like your system is running very smoothly. Sometimes, the water flows so smoothly through the strainer basket that you can't see any water movement. The strainer basket tank is filter completely to the top. If you didn't have water flowing through the basket, you would not have any water coming out the returns.

 Posted: 5/30/2017 

I'm a new pool owner and recently had the pool opened. However, when the pump is running, I do not see water going through pump strainer, but water is being pushed out of the in-ground pool jets. Is that normal or to be expected?

 Posted: 5/23/2017 

Great easy guide and does help thank you very much

InyoPools Product Specialist  Posted: 5/20/2017 

Chris - When you put water into the strainer pot, you are partially filling the intake lines. Some of the water you are adding is flowing back into the pool. When you close the system up and start the motor it will prime faster.

 Posted: 5/19/2017 

I opened the pump strainer box to clean it, reassembled, but can't seem to fill the water above the level of the pipe from the drain and strainer. I emptied 4x 5 gallon pails into it, the level rose while filling, then drained back down to the same level - any idea what I might be doing wrong?

InyoPools Product Specialist  Posted: 5/19/2017 

Cdcollins - Some filter systems operate without a relief valve. They are designed to relieve pressure automatically. Proceed and ignore references to a relief valve.

 Posted: 5/18/2017 

I don't have a relief valve what next

Anonymous  Posted: 5/17/2017 

wow, thanks - you weren't kidding, it took just about 10 tries to get this done before it finally took. thanks again, this was extremely helpful.

InyoPools Product Specialist  Posted: 5/10/2017 

lidia - If you pulled the vacuum out of the pool without disconnecting it, the pump is sucking air through the vacuum which causes it to loose prime. You have to disconnect the vacuum from the insert.

 Posted: 5/8/2017 

i cleaned my pool for he first time buying a hose and vacuum head, connect it to the insert where is a basket by pool,it was priming and then when we finished cleaning we tried to disconnect hose from insert it was stuck my daughter got the vacuum out of pool i noticed a different noise in pump and stopped priming i cleaned both baskets pump and by pool after that pressed maintence then turned it back on notice no water was going down like fountain like jacuzzi to pool let it on some hours noticed later still not on so think i messed up pump

InyoPools Product Specialist  Posted: 5/2/2017 

Still learning - Generally, when you fill the strainer basket with water, it doesn't fill all the way. It starts flowing back into the pool. But you have enough water in the pipes to prime the pump. If you had a lot of debris in your pool when you opened it, some of that might have partially blocked a pipe or the pump impeller. Debris in the impeller is a frequent problem. I would check that first. See our guide on "How To Clean Out a Pool Pump Impeller".

 Posted: 4/30/2017 

I had a hard time getting my pump to prime when I opened after winter. I finally got it going but I opened the pump to clean the basket, and now I can't get it going again. When I fill the basket it fills all the way to the top unti it overflows. It was doing that when I first opened when it wasn't working. Finally the water flowed freely and wasn't filling all the way up and it worked. I didn't do anything different and don't know to get it going again. Please help. TIA.

InyoPools Product Specialist  Posted: 3/20/2017 

Bonnie - Try blowing the clog out with a drain cleaner bladder. It's simpler, cheaper and most people have had good success with them. It’s most effective if you insert it at the pump going back to the pool. Any hardware store sells these bladders.

 Posted: 3/16/2017 

how can you remove problem in clogged pipe? Cannot prime pump, have tried all you have suggested.

InyoPools Product Specialist  Posted: 11/18/2016 

Alex Z. - Yes, you will have to replace the impeller from the old motor and reinstall it on the new motor. For a step-by-step procedure on replacing a motor, see our guide on "How To Replace the Motor on Your Pool Pump". Remember to buy an replace the motor shaft seal.

 Posted: 11/16/2016 

I believe that my motor just burned. It's been acting up for about 4 months know. it would struggle to start every time (would make a noise like it's about the start and then it shuts off again). Finally today it was doing it for few hours while i was at work and still kept doing it when i came home. It smelled like something burned and it was very hot (to the point that i had black marks on my sand filter thats sitting next to it). I purchase same exact motor online and will be replacing it this weekend hopefully. My question is, since i never did this before, do i need to remove impeller as well, or i can only remove the motor, put the wires the way they were and proceed with priming process? Thank you in advance