This guide will explain how to troubleshoot a pool pump that is not priming. The most common causes of pool pump priming issues are sucking air leaks in your pump housing or plumbing, and debris clogs. We’ll be focusing mainly on the suction-side of your pool equipment for this guide. The suction-side s all equipment and plumbing from your skimmers and main drains to your pool pump’s impeller.
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Robert Posted: 5/27/2022
We just opened our pool and left the pump running overnight not paying attention. We were cleaning the baskets as they were clogging from algae. After leaving it on all night we woke up and found the basket full, pump not pumping water and very hot. We shut everything down and cleaned everything. After pump cooled off we started it again. Now it will only keep prime for a few minutes for it looses it. Could we have damaged the impeller or diffuser? Or maybe we burned up the seal and it's stucking in air now? If I put the filter in bypass pump will prime but not if I leave it in filter mode.Reply
InyoPools Product Specialist Matt S. Posted: 5/27/2022
It could be any one of those causes; the best way to find it is to check for damage by opening and inspecting the pump. The fact that it won't prime when the filter is set for regular operation could signify you need to do a thorough backwash and rinsing.Reply
Helliife Posted: 10/14/2021
Pump won’t prime. I have poured water into the strainer box for about half an hour straight and still no raise in the water level. It will raise up over the strainer box occasionally, but when I pull the hose out the water level drops just above the top of the inlet valve. Hit the pump and the water gets sucked through the pump but no flow is created.Reply
InyoPools Product Specialist Matt S. Posted: 10/14/2021
Ok, you've done one thing from the guide. I suggest doing the rest of the steps we walk you through to find the issue. Everything I'd suggest is already written in the guide. If you do all that and then still can't find it, then I'd come back with a follow-up.From that basic description in the question, you may have a water (or air) leak or the water level in the pool is low. But you won't know until you do the other troubleshooting. How to Identify and Correct Air LeaksReply
Anonymous Posted: 10/2/2021
All of a sudden my pool is not priming when starting. if i open relief valve, within a minute pump starts to prime and than continues to run fine until next start and have to do all overReply
InyoPools Product Specialist Matt S. Posted: 10/4/2021
If the only way to get your pump to prime is to release a large amount of trapped air in the system, then I suspect you have an air leak. I begin troubleshooting by looking for the air leak on the suction side of your system. Follow the steps in this guide to find the leak - How to Identify and Correct Air LeaksReply
Chris Posted: 5/22/2021
Just bought a new pump as old one fried. Repeated ALL steps with no luck as pump will not prime. No air leaks, no water leaks, all joints and unions properly taped and/or glued. Lines full and not leaking, pump basket clean and full, skimmer clear, etc ,etc. Any ideas?Reply
InyoPools Product Specialist Matt S. Posted: 6/4/2021
Have you tried priming the pump yourself using a hose? How To Prime a Pool PumpReply
Melissa Posted: 5/17/2021
Opened pool for the third season. Started off with just the drains open on the suction side until the water level was back up. All was great. Opened our two skimmers today and the pump lost prime. Added a little more water. Now the pump is fine with the drains and one skimmer at a time open. As soon as we open two skimmers and the drain together it loses prime. Doesn’t matter which skimmer. Both are good in their own. Any time all three valves are open we pose prime. I backwashed and rinsed the filter and still have the same problem. Cleaned the skimmer basked and the basked at the pump. No luck. Any suggestions?Reply
InyoPools Product Specialist Matt S. Posted: 6/4/2021
You may have an air leak, which you should try to find using the How to Identify and Correct Air Leaks guide.Reply
Rich Posted: 5/1/2021
Just opened my pool, new pump installed last season, new filter cartridges and manifold this season. Pump won't prime. I've put a hose into the pump 2-3 minutes, I can even see the water flowing backwards through the skimmers. When I turn the pump on, it sucks with authority, but the water doesn't continue to flow and it doesn't prime. I've tried to open / close the suction valves, nothing seems to be changing. I don't see any swirl at the skimmer. If I open the pump lid, the basket area fills with water, then if I close and start the pump again - it will suck with authority until the water flow stops. Only thing that has changed are the filter cartridges...but I don't think the problem is after the pump. It almost seems like all the valves are closed, but then it wouldn't suck. I can also see water flow on the return side, so I'm stumped...everything appears to be "ok" (weir doors open, water level is high, etc). Any ideas?Reply
InyoPools Product Specialist Matt S. Posted: 5/14/2021
Are you sure you aren't confusing an absence of air bubbles in the pump strainer for it not priming? I presume no bypass circumvents your pump and filter, so water has to be pulled in by the pump and pushed out of the return.Also, are you sure you installed the correct cartridges? Some filter models have cartridges that are similarly sized, but the amount of pleats (and fabric used) is drastically different, affecting flowrate capacities. If a smaller cartridge was used it could explain the sudden dropoff in flow after a few minutes.Reply
Brian Posted: 1/27/2021
My pool has been decommissioned for about 12 months, have tried to prime by filling pump and by compression from inside the basket. No blockages it sucks initally for a couple of seconds then stops. Any advice thanks in advance.Reply
InyoPools Product Specialist Matt S. Posted: 1/28/2021
The guide mentions quite a few things to check. If your pool was out of service for awhile you should do those basic things before a more technical troubleshoot is attempted. If you have done more than try to prime the pool, then please provide more info.Reply
Rebecca M Bresnyan Posted: 10/4/2020
is is possible to have something stuck in the line under the concrete?Reply
InyoPools Product Specialist Matt S. Posted: 10/5/2020
Yes, you can get a blockage there as well. Wherever there is liquid going through a pipe, there is a chance of a blockage. A plumbing snake or plumbing bladder would be a good option for clearing a blockage.Reply
Mike Posted: 8/16/2020
Just installed new motor. Matched exact one that burnt out. Pump will not self prime. Nothing else changed. Is there a switch on the motor?Reply
Bronwyn Beukes Posted: 9/20/2020
Hi Mike did you get it sorted? We are having a similar issueReply
InyoPools Product Specialist Matt S. Posted: 8/21/2020
Have you tried any methods to help the pump prime itself, like filling the strainer with water? Does your filter have an air relief; and if so, is it open? I would also check any plumbing valves to make sure they are set to pull water from the main drain.Reply
Danielle Posted: 8/11/2020
We have just replaced our Pentair Superflo VS pump. It has been installed and seems to work just fine, except that our skimmer baskets are not pulling water. We have cleaned the impeller, the cartridge filters and bleed the air, and cleaned the salt cell. Any ideas for more troubleshooting?Reply
InyoPools Product Specialist Matt S. Posted: 9/3/2020
Have you made sure your diverter valves are open on the skimmer line? To help pumps prime, an installer will set it so only the main drain is drawing water. If they forgot to put it back to open, it could explain your flow problems.Reply
Fred Posted: 7/7/2020
I have a problem.I have a cartridge filter,when I install the filter the pump is sucking water for 3/4 of the capacity.The kreepy is hardly moving. When I remove the cartridge filter and let the pump running it is sucking water for 100%. I checked everything but can not find the problem. Do you have a solution for this problem ?Reply
InyoPools Product Specialist Matt S. Posted: 10/6/2020
It definitely sounds like the cartridge is restricting flow. Is this a new cartridge or an old? If it is old, you probably need to give it a chemical soak to clear out debris. How To Chemically Clean a Pool Cartridge FilterReply
John Posted: 2/15/2020
80’s gunite pool, new house for us. Mechanical equipment about 10 years old. Variable speed pump, cartridge filter, heater, pool and spa. At some point someone repiped things, my main drain has no suction. There are two pipes coming up out of the ground near the pump. One is 1 1/2 inch, the other is 2 inch. These are capped off but have notches cut into them below the cap. Someone explained this is how the spa aerates. I determined that the 2 inch pipe actually aerates the spa jets. The other apparently does nothing. I recently pressure washed my four filter cartridges. They had probably not been cleaned in at least five years, maybe ever. My Hayward variable speed became a monster at 3300 rpm and the 1 1/2 inch capped but notched pipe started spraying water out at anything over about 2000 rpm. I think the actual efficiency of the pump was at least half before I cleaned the cartridges. I cut this pipe and capped it permanently as I could not determine its use. This did not seem to have any detrimental effect on anything. However, my pump has problems priming, as if it’s trying to push a head of air, and often will blow water backward through the suction lines when the pump is shut off. When it primes, it runs like a bandit, but it seems to be compressing air in my filter housing. I can bleed air from the filter until I get to water, but this seems not to be a common thing to have to do. Basically, it seems like my pool ran better with clogged filters, as not I seem to have nothing but problems with back pressure and priming, whereas before cleaning, I never had issues at all other than looking at a pressure indicator deep in the red on the filter. What might I have done wrong, and what the hell do you think that 1 1/2 inch pvc blowing water might have been.Reply
InyoPools Product Specialist Matt S. Posted: 2/17/2020
First, what troubleshooting have you done from the guide? As you say, there is air in the system; most of the guide discusses how to prevent air from getting in your pipes. What steps have you taken to detect or correct air leaks? You can also try this more in-depth guide on finding and correcting air leaks: How to Identify and Correct Air LeaksThe act of cleaning the filters should not cause pump priming issues. If the filter or pump were reassembled incorrectly (lid or clamp is not tight enough, the gasket is pinched) that is most likely the issue.Also, did this priming issue only start after you cut the strange with no function?Reply
Michelle Posted: 10/20/2019
New pool.owners here Every time we clean the filters we have an issue w priming from full pool suction. If I adjust to partial spa suction it gets it moving but from full pool it causes dry prime alarm to sound. Any suggestions?Reply
InyoPools Product Specialist Matt S. Posted: 10/21/2019
Your water level may be too low, which allows the pump to gulp air. You can also still check the plumbing elements we mention in the guide to determine if they may be causing the air in the system, i.e., valves, unions, joint adapters.Reply
Jean Posted: 10/15/2019
just changed my old 1 speed to a variable speed ECM27SQU. After 1 full day of operation, here are my results : 2h at 3450 pump is primed at 98% (small size air bubble); 2h at 2600 pump does not quite prime (air bubbles in most of the lid); 8h at 1725 and there is little/no priming (about 4-5" of water in the basket; almost no pressure at the filter meter reading, but water circulates). Also at 3450, my inline cleaner was working, but once it dropped to 2600 (and of course to 1725) the cleaner stopped working; i then closed the cleaner valve hoping to suck more water out of skimmer and main, but that did not change much; pump was still not priming anymore. I then did the soap water test and could not find a leak around any fitting or valve or lid. Water is about 1/2 way to the skimmer. What should i do or look for next ?Reply
InyoPools Product Specialist Hector F. Posted: 11/4/2019
So with a variable speed motor you may not see a pump with a full prime as the suction has decreased. When the RPM's are lower and the suction is lower, your cleaner potentially not having enough suction is normal. Not all pool systems will generate enough suction and water pressure in the lower RPM's. Each swimming pool is different however after testing the settings, not having any air suction leaks and seeing water flow back to the swimming pool in at least some of the lower RPM's you do not have to be concerned.Reply
David Kerry Posted: 9/4/2019
My pump looses suction within a minute whenever I connect the hose to vacuum the pool. The pump runs 6 hrs every night with no problems. As soon as the hose goes on the skimmer box cover , the pump noise changes as if cavitating . I bought a brand new hose and still the same. Tried a new vacuum head also , as old one warping . I replaced the 8 yr old pump with the same ( Davey Silensor ) because it had a broken impeller when I opened it up to investigate. I am baffled as there is no obstruction. Has anyone got any idea ?Reply
InyoPools Product Specialist Robert M. Posted: 9/4/2019
Hello David - Do you have an above ground or inground pool?Reply
David Posted: 9/4/2019
I have a 55,000 litre concrete in ground pool that is 25 yrs old.Reply
InyoPools Product Specialist Robert M. Posted: 9/5/2019
The pump is not receiving enough water when the hose is plugged into the skimmer. Try opening up the main drain more so that it can pull additional water.Reply
C. Lombardo Posted: 8/7/2019
I think he went through everything and i had 3 things that he mentioned was the problemReply
Carol Posted: 8/2/2019
This guide is awesome. Thank you for making it.Reply
Anonymous Posted: 7/7/2019
I cant get my filter to prime. I sit there and fill the water for 5 minutes or more and it never fills all the way up. After I turn it on it immediately drains from the filter and starts sucking air. I tried all methods above. Please help.Reply
InyoPools Product Specialist Matt S. Posted: 7/8/2019
This is a more thorough guide on How to Identify and Correct Air Leaks. If you still can't find the issue after following the guide then you may want to try calling a professional to take a look.Reply
Scott Posted: 6/19/2019
I have a pump that will prime but loses it when the filter basket is almost full. At that point the water in the basket area drains away and I can see the water coming from the pool to start filling for prime. It just repeats that cycle and never runs in normal filter mode (or backwash for that matter). Any thoughts? Thx in advance ScottReply
InyoPools Product Specialist Matt S. Posted: 6/20/2019
It sounds like you have a sucking air leak. Have you checked any of the things mentioned in the guide? How to Identify and Correct Air LeaksReply
Donna Thomas Posted: 6/2/2019
Pump not getting enough water to returnReply