Prime Suspect: Why Your Pump Won’t Start

Air is the invisible enemy of a pool pump, and once it slips into the system, your prime is gone, your filter pressure dives, and your day gets longer. We zero in on the real reasons pumps refuse to prime and share the simple, reliable fixes working pros use to get water moving fast.

We start with the most common failure point—the pump lid O‑ring—and explain how age, dryness, and missing gaskets break the vacuum seal. From there, we tackle heat damage: low water leads to dry runs, scalding housings, warped baskets, and tiny leaks at threaded fittings and unions that are almost impossible to see. You’ll learn practical detection tricks, why high-heat fittings matter, and when a quick temporary wrap can confirm the diagnosis before you re‑plumb.

Then we walk through two priming methods that save routes. If you’ve got an attached spa, use spa suction to pull a quick prime and feather the valve back to pool without losing it. No spa? A drain bladder floods the skimmer line so the pump catches a full water column. We also cover low PSI caused by clogged impellers, how to free debris with a long screwdriver, and when to pull the motor for a proper clean. Add in diffuser wear, telltale turbulence, and the often-overlooked Jandy valve O‑ring, and you’ve got a complete field checklist that solves 95% of priming headaches.

• checking the pump lid O‑ring and proper lube
• finding heat‑warped fittings and union leaks
• using plastic wrap or tape to confirm air leaks
• spa suction feathering to restore prime
• drain bladder flooding for skimmer lines
• clearing clogged impellers with a screwdriver
• inspecting diffusers and wear rings for turbulence
• choosing and using lid removal tools safely
• diagnosing worn Jandy valve O‑rings and debris
• knowing when to stop and return with time

Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support. Learn more at swimmingpoollearning.com

Support the Pool Guy Podcast Show Sponsors! 

HASA 
https://bit.ly/HASA

The Bottom Feeder. Save $100 with Code: DVB100
https://store.thebottomfeeder.com/

Try Skimmer FREE for 30 days:
https://getskimmer.com/poolguy 

Get UPA Liability Insurance $64 a month! https://forms.gle/F9YoTWNQ8WnvT4QBA

Pool Guy Coaching: https://bit.ly/40wFE6y

Chapters

• 0:00 Priming Problems Framed
• 2:32 Why Air Stops A Prime
• 2:58 Lid O‑Ring Checks And Fixes
• 4:49 Heat Damage And Hidden Air Leaks
• 7:27 Temporary Seals And Re‑Plumbing
• 10:27 Two Reliable Priming Methods
• 14:39 Clearing A Clogged Impeller
• 17:41 Stuck Lids And Proper Tools
• 20:07 Diffusers, Wear Rings, And Turbulence
• 21:46 Jandy Valves And Final Checks

Transcript

SPEAKER_00: 1:03

Hey, welcome to the Pool Guy Podcast Show. In this episode, I'm gonna go over some problems you may have with priming a pool pump. And I'll give you some of the solutions that should work about 95% of the time. Nothing is 100%, but these should work most of the times when you can't get a pool pump to prime. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support. From me, I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingpoollearning.com. In general, most of the time the pool pump is not priming because there is something that is inherently causing air to get into the system at some location. Since the pool pump needs a completely closed, watertight system to operate, if there's any air getting in there from any source, the pool pump won't prime up. Now typically the air source, the first thing that I would check for is the most simplest thing to check for, which is the pump lid O-ring. And I remember one time, actually more than one time, but this one time I was at a pool and it was a whisper flow pump, and the customer said the pump is not running. So I went over there and I checked it out. I took the lid off, filled it with water, put the lid back on, and it wasn't priming, and I was perplexed because this pool never gave me any problems before. And so I'm standing there looking at the pump, and then I look at the ground and I noticed that the O-ring for the lid is right there on the ground. And lo and behold, the customer saw some debris in there. They decided to clean it out. And when the Pentera Whisperflow lid O-ring starts to wear out a little bit, get old, they don't kind of get flattened, they actually fall right off the pump lid. And so what had happened is the customer took the lid off, cleaned the pump basket, put the lid back on, but the o-ring had fallen off, which is again common when they start to get old. And so here I am wasting 10 minutes trying to get this thing primed when the solution was, and I should have looked at the lid myself, that's on me. The O-ring wasn't even on there. So lid O-ring is the first thing that I you'll notice as a problem. Always carry a bunch of different lid O-rings on your truck for the pool pumps on your route. If you have like a Hayward Super 2 pub, Panther Whisper Flow, Panther Superflow. Having a a few of those O-rings in your truck so you can change them whenever you need to, is ideal and a great way to make sure that that problem doesn't cause the pump not to prime. Sometimes if you just lube it up really well with magic lube, that will also solve the problem. So that's the first thing I check is the pumplet O-ring. Now something else that may not be quite as obvious, and this happens quite often when the pool runs low on water, the equipment starts to get hot. I've taken off pump lids and opened them up where the water is like boiling hot from the pool being low on water. And I pulled out the pump basket, and it looks like a shrunken head kind of thing you see in the movies, you know, the cannibals in Africa, but it's actually the pump basket all shrunken and kind of melted, and that's because it got super hot in there. And when these pumps run dry, they do produce a lot of heat. And so one thing that can happen is that the threaded fittings on the front and on top, the intake and outlet, slightly melt a little bit. A lot of the pool pros like using the high heat Granger gray intake and outlet threaded parts on their pumps. I prefer those myself as well. They tend to withstand the heat better when you the pool runs dry. But nevertheless, if there is a little bit of air getting in there, you really can't tell. There's different tricks like you know putting shaving cream on there or soap and water as you see bubbles, or lighting a match and seeing if the smoke gets pulled in there, things like that. But what I do, and this is getting rarer and rare to be able to do in California because the plastic bags are pretty much banned everywhere. But you can use trash bags for this, like the thinner trash bags, not the heavy-duty black ones. But just tie a white trash bag, you know, what is it, a 20-gallon trash bag, around the intake and outlet. You can also use the professional grade electric tape, not the stuff you get at Home Depot, but more of a plumbing electrical tape, and wrap the inlet and outlet of the pump with that. And if the pump primes up fine, then more than likely there is a slight melt in that threaded part letting air in. So the solution for that, of course, is to re-plumb the intake and outlet of the pump. I usually re-plumb both of them because even though you don't see it on top, it is probably a little bit melted. But the intake is probably what's causing the problem, and or even the outtake, I should say, is causing the problem, and it's not letting the pool prime up because water because air is being sucked in there along with the water when it's trying to prime up. And so that's the solution there. Sometimes it's on unions, and those union o-rings melt from the heat as well. So changing the O-rings in the unions is a good way, also. If your pump has unions on top and in front, changing those o-rings in a union will also solve this problem with the pump overheated. Let me share with you some priming methods. If you run into this problem, and let's say you tied bags around the front and you you just need to get it primed up now, you change the lid O-ring, and of course that means that a lot of air is in that pool line, so it can't really pull the water from the skimmer because of all the air in there, and that's why even if you put water in the skimmer in the pump basket, I should say, the wet end, and put the lid on, you'll see it turn on and suck dry again, and there'll just be like a little bit of water down there, but mostly air in there. Because it really can't pull the water, even if you fill up the pump pot with water, it just can't pull it to the pipe. There's a couple of solutions here. The first one, if you have an attached spa, which is usually most pools in my area have an attached spa that draws from the same motor or pump. Go ahead and put it in spa suction mode. You can leave it in pool return mode if you want, it's not a big deal. But just turn the valve so that it's gonna be sucking from the spa instead of sucking from the skimmer. So once you do that, go ahead and turn on the pump. And usually it'll prime because there's water in that line already, and it could also be gravity because the spa is elevated, but typically there's water in that spa line because it didn't run dry, and it should prime up pretty fast. Within about a minute or 30 seconds, you should have the pump priming. So now it's sucking from the spa, returning to the pool, which is fine. Now you want to get the valve. If it's a jandy valve, you can just turn it yourself. And as you start turning it back towards pool section, you're gonna see the pump cavitate. So stop, turn it all the way back to spa section again, then turn it again until it starts cavitating again, which means there's air and water in the pump, and you'll see it kind of struggling. Then turn it back to spa section. Keep doing that, and you're gonna get further and further to the pool section, and eventually you'll get full pool section and it'll fire up and you'll have no problem. Now, if you have a valve actuator, you can do the same thing. Just flip the switch on it and then stop it, flip it back whenever you start to get too much air in there. And that's kind of a really simple way to prime a pool if you lose this if it loses this prime and you have an attached spa to it. It works like 95% of the time. I've never really had a major failure with that, and it's just a little trick priming from the spa versus priming from the skimmer. Now, if you don't have an attached spa, what you can do is get a drain bladder. I prefer the cloth one, they're they're more expensive, they're like 30 or 40 bucks at Home Depot. You can get a rubber one as well. If the customer has a garden hose, by the way, you should always carry a spare garden hose with you in case the customer's garden hoses are broken. Most of them, the fronts like smash down and you can't put a nozzle on there. It's kind of weird. But like every other pool hose that I'm trying to use at a customer's garden hose that I'm trying to use at a customer's house has like the end of it crushed or broken or whatever. And I mean, whenever I get to a customer's house and they have like a beautiful garden hose, it's like you know, the pink color with the nice brass ends and everything attaches and it works great. I'm thankful for that. But very rarely you're gonna find that. So have your own garden hose, attach a drain bladder to it, stick it as far into the skimmer as you can with the water off, and then once you've found that the drain bladder can't go any further in, turn on the hose and let the water run for a minute or two. Now you're gonna see you can take the pump lid off, also, go over to the equipment and see the water filling up. So it should fill up the whole line into the pump, and it should be full falling over the edge of the pump, like flowing over the top of it. Then you put the lid on the pump, and this takes a little bit of kind of fast action or maneuvering, but go ahead and turn the pump on, and then stand over there by the garden hose, uh hose spigot or bib, and once the once you hear it start to prime up, turn the drain bladder off, and it has to be timed pretty well, otherwise you could burst the drain bladder. I've had this happen before, but especially the ones that aren't cloth that are rubber. But turn the hose off once you see it priming, and then pull the drain bladder out, and you should have a good prime there. So that's kind of the two methods of priming a pool. When you've lost its prime, you've replaced the the bad o-ring on the lid, or you've you know you've done something else to get it working, and you need to prime it at that point. So that's the way we do it out there. There's those two methods that are highly effective. Another thing that you will run into is that some debris gets through the pump basket into the impeller. So when you get to the stop, the pool may be running, but the psi on the filter may be down to like three or four or five, it's really low. But you'll see a little bit of water in the pump, and you'll see the pump sucking it, but you'll see like 70% of inside the pump is air with a little bit of water, and that's why the PSI is so low because it's really not filling up the filter at that point. What that is is usually debris in the impeller, and it's pretty easy to clear out. One thing that you can do, I just carry a screwdriver that has a pretty long neck on it or head on it, just a flathead screwdriver, and you put it in there and you just first okay, I'll start over. You turn the equipment off, make sure it's off, then you take the pump basket out, and then you'll take the screwdriver and you'll spin the impeller with it. Some people create like a little tool with a hanger, but a screwdriver is fine, and just spin the impeller a few times, and it once you get it spinning freely, you're gonna hear it gurgle, you're gonna hear the water gurgle gurgle in there, and then that's kind of an indication that you cleared the debris out of there. So go ahead and fill up the pump with water, put the put the basket back in first, fill it up with water, put the lid on, and then fire it up, and it should prime up pretty immediately. Now, of course, if you lost if it's lost its prime, then you could do the steps I talked about earlier to get it primed up. Once you clear the impeller, the PSI should be back up to 20, and you should have really good flow with really no air in the lid, and you should be good to go at that point. Sometimes there the debris in the impeller actually clogs it up around the impeller where it is in the seal plate, and you have to take the motor off, and then you'll have to inspect the impeller physically and kind of clear debris out. Not super common in my area, but um I've seen it happen before where like pellet debris gets stuck in the impeller and it jams it. And of course, taking it taking it off and cleaning the impeller with your hands is the best way to do it in that case. But again, most of the time, like 90% of the time, when you spin it with a screwdriver, it's gonna clear the debris in there. And typically the pump basket might have a crack in it or a tear in it. Replace that before you put everything back together, of course. Or if you don't have a pump basket, just make a note of it for next time. But the debris in the impeller will also stop it from priming, very similar to an air leak, and very similar to maybe the pump lid o-ring being worn out. Sometimes the pump may be fine and priming, and you don't have a problem with it. The problem with you have is that you can't get the lid off the pump. This happens a lot. There's special tools that they make for some of these lids, like the uh haywear super pump or haywear super 2 pump. You have a special tool you can use to get those lids off. And then Penthare, of course, the whisper flow pump. Sometimes those lids are on extremely tight, you can't get them off. And don't hurt yourself by like hitting it with your hand to kind of hammer it. Just carry your rubber mallet with you. Go to the 99 cent store, Dollar Tree store, get a nice rubber mallet, and then whenever you get to a Pentair Whisperflow where the lid is on there really good, just hit one end of it with the mallet that's the sticking out, and that should loosen it up, no problem. So you may run into that where you have a pump lid that's stuck on there, but a lot of lids or a lot of pumps do have a tool that goes with it, so maybe do some research and see which pumps you're gonna need a tool for. And they have various ones, they have metal ones, and then they have the plastic one that Hayward makes. I think it's the Hayward SP3100T, and that's for those Haywood pumps. And the one that's made out of metals a little bit more universal, you can use it for other pump lids as well. There's some older ones that you may need to use it for. Some have like a groove in there. I've seen those like down the center, and you can actually stick a long screwdriver, a big screwdriver in there, and you can turn it that way. But definitely get some of these lid removal tools and have them on your truck so you can use them to get the lids off pretty easily that are stuck on there. Because believe me, without these tools, you cannot get some of these lids off. There's just no way humanly possible to remove them. And I've I've tried different methods without the special design tools, and it's pretty much futile without them. You just need those to get these lids off. Once in a while, you're gonna run into a pump where the lid doesn't go on too well, and sometimes if there's air in the system, it'll actually blow the lid off or make the lid come loose. I've had this happen on a couple of accounts, and I couldn't figure out where the air was coming from in one of these accounts, and I know this is pretty tacky and it's kind of like a really bad MacGyver kind of fix, but there was one super super uh Hayward Super 2 pump where the lid kept coming loose and I couldn't figure out what was going on. So what I did is I just put a giant cinder block on top of it, and it seemed to work. I've never had a problem with that one popping off. I've had a few Penta Whisper Flow lids of Air gets in the system, and there's like a lot of pressure. I've had those pop off as well. It's kind of strange when a customer calls you and says, hey, the pump lid popped off, and you get to the pool, and sure enough, it's not it's off. So, what I usually do with those whisper flow lids where they're they tend to pop, I'll just get my rubber mallet and I'll just do the opposite. I'll just pound them on so that there's no chance of them coming off. But typically that's not the problem you're gonna have. The problem you're gonna have is the opposite, not being able to get the pump lid off versus pump lids that may be loose and can pop off by themselves. And the last thing I'll note is that sometimes you have a diffuser issue where the diffuser is worn out, and some of the symptoms are similar where it's sucking a lot of air in there and it's not pulling a lot of water. And if you tried a lot of different things like changing the pumplet o-ring, making sure there's no air leaks in the discharge and intake, making sure there's nothing stuck in the impeller. Sometimes it is the diffuser. If you have like again, this Hayward Super 2 pump has like a clear white wear ring, and sometimes you'll find that like you when you put the screwdriver in the impeller, you'll feel that plastic wear ring when you're trying to spin it, and it could jam up the impeller on that wear ring as well. But there are some occasions where the actual diffuser has been worn out, and that's the part that goes in front of the impeller. And for some reason, Penta the Whisper Flow uses like these little Allen screws on there. Can ever figure that out? It's kind of irritating. Takes you like 20 minutes to get the diffuser off, but basically, you know, the diffuser can wear out as well. So that's like one more thing to check. If you've checked everything else and you're still seeing like kind of like air and water, but it's more like a turbulent kind of air water when a diffuser is worn out. It's I don't know if that makes sense, but there's a lot more turbulence in there when that's not working because it's not really diffusing the water, so to speak, properly. So that's another thing to look at as well. If you do all of this and you're still having trouble, somewhere you can look also for air getting in is over at a jandy valve. Sometimes those o-rings do wear out, they're pretty durable and long-lasting, but if those o-rings do wear out in the jandy valves themselves, they're pretty thin and they'll let air in also, and it could cause a pump, not the prime for that reason as well. Sometimes there's also debris caught in the jandy valve as well. So take that off. There's what eight or ten screws on top, pull it off, and then you'll see if there's any debris in there, and also inspect the o-ring in there to see if it's worn out and loop it up if it doesn't look worn out, put it back in there, and that might solve the problem. But also carry some of those jandy o-rings with you as well. And the reason why I say jandy is because most builders, even though they put pent air equipment in or haywood equipment in, they'll still use the jandy valves because they are superior. So you'll find that at least in my case in my area, 90% of the valves are jandy valves, and there's a few Hayward valves and pentair valves, but majority of those are jandy valves, and they're usually pretty good and they're pretty durable. So that's something kind of as a last resort to look at. And then finally, don't spend more than five or ten minutes trying to get the pool primed up. If you can't get it working, leave everything shut off, and then maybe go back there on a day where you're fresh, we can look at it and get a better perspective because you're frustrated, time's ticking, you haven't done anything at the pool, and you have other stops to get to. So after about 10 minutes maximum, you want to cut it and just forget it at this point and get back to it later when you have more time again to try to troubleshoot it and get the pool, get the pump primed up. Looking for other podcasts, you can of course subscribe to my YouTube channel Monday through Friday, have an episode there for you. And if you're if you go to my website, SwamiproLearning.com on the banner, there's also a podcast icon with over 1700 podcasts for you there. And if you're just in the coaching program that I offer, you can learn more at poolguidecoaching.com. Thanks for listening to this podcast. Have the rest of your week and God bless.