Home / Articles / 5 Biggest Pool Pump Mistakes

5 Biggest Pool Pump Mistakes

5 Biggest Pool Pump Mistakes

The pool pump is literally the heart of your pool’s circulation system.  But just like our own hearts, we have a tendency to neglect the health and well-being of the pool pump and then freak out when it’s not working properly.  There are probably dozens of pool pump mistakes out there. . . here are our top 5.

Not Cleaning Pump Basket

Blog Image - Pump Basket Leaves (200 x 200)Let’s start with the very basics.  The pump strainer basket exists to catch debris but it can’t clean itself.  You need to reach in there and get the gunk out.  If you don’t, the pool will have decreased water flow which means reduced filtration and ultimately, the dreaded algae bloom.  The pump basket should be cleared out weekly and even more frequently during the fall and spring when there is more debris in the pool.  Learn more here about how to clean your pump strainer basket.

Running Pump Too Little or Too Much

Some pool owners, desperate to save money on their electric bills, actually cost themselves more in the long run by not runningBlog Image -Pump Timer (200 x 200) the pump long enough.  To maintain water quality and safety, all of the water in your pool should be turned over (meaning filtered) once a day.  Depending on the gallons per minute your pump is moving, this usually takes 8 – 12 hours.  If you don’t give all the water a chance to pass through the filter, you can end up with dirty, cloudy water, algae and the need to spend more on chemicals and maintenance than you would’ve given to your utility company to run the pump a little longer.

On the flip side, there is running the pump too long.  Some believe in keeping it going 24/7 which might be necessary under certain conditions but for most pools is just wasteful overkill.  It drains both energy and money while causing unnecessary strain on the pool pump motor.  Your pump will burn out more quickly and require replacement of parts or the entire unit.  Plus, you are driving your neighbors crazy!  Give them a break from that humming motor and save some money in the process.  For standard residential pools with moderate use, you only need to turn over all the water once in a 24 hour time period.  If you are into the math behind pump run times and savings, read our How to Reduce Your Pool Pump Energy Bill guide.

Sizing Pump Incorrectly

There is a very persistent myth in the pool world that the higher the horsepower, the better.  As a result, it is probably safe to say that the majority of pools have oversized pumps.  We regularly hear from customers with a relatively small pool (~ 10,000 gallons) and a pump that is moving 2 – 3 times the gallons per minute required.  This means unnecessarily high electric bills and a lot of wasted energy.  Too large of a pump can cause poor filter performance and even damage it, if the filter is not also oversized accordingly.  Another possible consequence is pump cavitation in which bubbles form in the water inside the pump and then burst with great force, resulting in damage to the impeller and other internal parts.

Conversely, some pool owners try to save a few bucks by buying a lower horsepower pump that is too small for their pool’s demands.  This is especially true when a spa and other water features, such as deck jets or waterfalls, are tied into the pool pump.  Throw an automatic suction cleaner into the mix and that undersized pump is overloaded.

The bottom line?  Do the math to calculate how many gallons are in your pool (and spa if applicable) and how many gallons per minute are required to filter all of that water in 8 – 12 hours.  Then consult the manufacturer’s pump performance charts to determine what pump actually meets your needs.  Or skip all that, contact us and we’ll do the legwork for you!

Not Priming Pump / Running Dry

Most in-ground pool pumps are self-priming but do not mistakenly think this means your pump can initially prime itself.  “Self-priming” refers to the pump being able to reprime, and this depends upon a proper initial prime and maintenance.  Priming a pump means filling the intake with water.  Then upon start, the pump will push any air out through the discharge.  Read our step-by-step priming guide for all the details.

A loss of prime will cause the pump to run dry which you never want to do.  Keeping an eye on the pool water level is a must – don’t let it drop below the skimmer opening.  If the pump has no water to pull from the skimmer, it will draw air instead and lose prime which leads to running dry.  At the least, this will ruin the motor shaft seal which is what prevents water from getting inside the motor.  If it keeps running dry, the pump heats up and so does the water inside.  Commence melting plastic.  The motor might survive due to the high temp sensor kicking in but the wet end of the pump will be a casualty.  If your pump has run dry and appears to have survived, replace the shaft seal!

Not Changing the Shaft Seal During Motor Replacement

Blog Image - Shaft Seal (200 x 200)I literally grind my teeth over this one.  Replacement pool pump motors are an extremely popular product for us – and with good reason.  In the majority of cases, when a pump fails, the wet end is fine and only the motor needs to be replaced.  Since a pump motor is roughly half the price of a new pump, it makes often sense to keep the existing wet end and just buy a new motor.  Especially true for DIYers who don’t have to pay an installer.

But so many people buy just the motor and neglect the small yet extremely important shaft seal.  This seal keeps water out of the motor (water inside motor + time = failed motor).  Yes, your existing motor will already have a seal on the shaft and it might appear to be in good shape and ok to reuse.  However, shaft seals warp over time.  If you install the old seal on a new motor, there is a good chance it will not mate properly, leading to leakage which voids the warranty on the new motor.

So don’t skip the new shaft seal!  Depending on the pump model, you’re looking at about $15 – $30 to protect a new motor that is worth much more than that.  Invest those few extra bucks – you will not regret it.  While you’re at it, motor replacement is a great opportunity to upgrade other internal parts most likely to fail.  Check for our complete tune up kits, available for many of the most common pool pumps.  These include the shaft seal, along with o-rings, gaskets and lubricant.  For help with replacing the seal, check out our how to guide and video.

author avatar
Matthew Simmons Technical Writer & Pool Product Expert
Swimming pool expert at InyoPools and host of Poolside Chat, brings over a decade of experience in the pool industry.

Related Videos

314 responses to “5 Biggest Pool Pump Mistakes”

  1. Neal Avatar

    I was using the vacuum on our above ground 4ftx28ft pool for the first time, it has alot of sand in the pool from the installation. The skimmer basket for blocked and I shut the pump off really fast. Took the vacuum out, primed the pump and when I turned it back on, it was making a humming sound. I am wondering if the impeller is bound by something. Unsure of next steps.

    1. Matthew Simmons Avatar

      Have a read of this article and the guides it mentions a few things that it could be: Pool Motor Troubleshooting Your motor may have just overheated if it was running dry, let it sit for a bit to cool off then try it.

      1. Neal Avatar

        Thank you so much for your help!

  2. Nelson Avatar

    my pool pump heats up when i use ac source from my local power supply but runs very well on generator. what could be the problem ac source is 247 v all the time but drops to 160 when i turn on the pump

    1. Matthew Simmons Avatar

      Are you using the same lines to connect the motor to the generator, and the motor to grid power? The drop in voltage and subsequent overheating may be a sign of one of the 220-240 lines connected to the grid being damaged, causing the motor to draw more amps, and therefore create more heat. I would try running new lines to the motor.

  3. Kim Avatar

    I have a above ground pool tried too turn pump on high and water started too coming out of the back of pump

    1. Matthew Simmons Avatar

      Like through the motor? If so, it seems like you have a bad shaft seal or a cracked seal plate. You’ll have to open the pump to be for sure, but take a look at this how-to guide to give you an idea how to replace a shaft seal: How To Replace a Pool Motor Shaft Seal,

  4. Kat Avatar

    I took the top off the pump 2 clean it out. When I put it back on there is a small leak. Should I turn off the pump until I can have someone help me or will it be fine with a small leak thru the day?

    1. Matthew Simmons Avatar

      Is the leak coming from a crack in the casing or from a leaky gasket? You can still run it but you will have to keep an eye on it just in case it gets severely worse. Figure out what the source of the leak is, and fix it asap; a small leak can turn into a gusher in no time.

  5. MBowen Avatar

    The pump to our pool kicked off when the water from the 2nd pool filter overflowed as I was priming it.
    It hasn’t turned on since. It’s been about 40 hours

    1. Matthew Simmons Avatar

      Was the motor flooded with water, or did it flip the breaker?

      1. Nik Avatar

        Hi, I can’t find an existing post or answer related to my problem…. pump fell out from bottom of skimmer basket on above ground pool, so of course water flowed (quickly!) over the top of the pump before we were able to lodge it back in place. It’s a cheap Walmart metal frame pool, 10 ft. Pump didn’t turn on. We are going to try to let it dry out, but is there anything else we can do?

        1. Matthew Simmons Avatar

          I’ve never fiddled with one of of their pumps so I’m not sure how much you can do with it once it is in that condition. But yeah, I would let it dry out for a day or two; then you can figure out if you will need a new skimmer or a new skimmer and a new skimmer and pump.

  6. Dee Avatar

    We have had an above ground pool that we purchased at Walmart last summer. The pump was working last summer but we put the pool up today and the pump doesn’t seem to be working. Does the pump need water to turn on? I mean like does water need to run through it to turn on? We have it plugged up but it doesn’t seem to be working. I’m trying to see if I should purchase another pump or not.

    1. Cyrissa Avatar

      Did you open the no at the top of the pump to let the air out? You have to do it until you see water come out and then the pump will turn on

    2. Matthew Simmons Avatar

      No, water does not need to be in the pump for it to run but since it is a an above ground pool water should freely flow to the pump as it is installed below the water level.

      When you try to turn on the pump, does it make a sound, pop the breaker or does it do nothing?

    3. Dunbar Avatar

      If the pump has a GFI on it the GFI might be wet causing it to be inoperable. Cut the plug end off and give it a new end. Always make sure that your new plug is always plugged into a GFI receptacle after replacing though…. ZAP!

    4. Bree Avatar

      It should come on even with out water. Same thing happen to me.

  7. Jay Avatar

    we treated the in ground pool with phosphate it recommends that the pool run for 48 hours straight, but noticed the pressure psi from 12 to 25, would we ruin the pump if left running all night and pressure becomes higher?

  8. Molly Avatar

    Thank you much for your quick response

  9. Molly Avatar

    Hi…. I have a new Hayward pump above ground pro matrix….. The water in the pump basket just misses the very top so there is stil a swirl of water….. It is almost full but not ….. Pressure perfect!…. Hoses changed… Everything seems tight…..no air bubbles in return….. Is this ok???

    1. Matthew Simmons Avatar

      If pressure is fine and there are no leaks then I would leave it alone. You can try poking around, but if it is not broke, don’t fix it.

      1.  Avatar

        I have the same issue with the water looking like it’s just barely to the top of the pump, but my pressure is low.

        1. Matthew Simmons Avatar

          The reason you pressure is low is likely because the air is causing it to be low. Check the line for pinhole air leaks and be sure the water level is at the correct height for the skimmer.

          1. Melinda Clemons Avatar

            I forgot to turn off the pump while cleaning the filter. Now the pump won’t run. HELP!

          2. Matthew Simmons Avatar

            I’ll need more information to go on than that. Did the pump run dry? Or, did the pump get splashed with water from a leaking filter?

            Did a breaker trip? If the pump ran dry, is there any obvious damage to the pump housing like melted parts?

      2. Lisa Avatar

        Hi Matthew, I wanted to ask about air in the top of the pump. Brand new pump installed, new pipes needed and can see air in top of pump. No water leaks but I assume this must mean small air leak in new pipe seals. Should I ask the installer back?

        1. Matthew Simmons Avatar

          The cause for concern is the size of the bubble. Some pumps have a few air bubbles that bounce around the top of the lid. If you have a couple of penny sized bubbles in your pump lid, then it probably is not an issue to be concerned about. But if the bubble is the size of most or all of the pump lid then you have a problem and need to find the leak.

          If your bubble is big, have your installer come back out, or read this how-to guide: How to Identify and Correct Air Leaks

          1. Li Avatar

            Wow. Thanks for such prompt reply. There are 4 quarter sized bubbles. I was worried the water would leak out overnight due to airleak but it held. There are now lots of tiny bubbles in chlorinator which I didn’t observe with last pump. There must be an air leak right? I can’t clear the air with the filter bleed but it doesn’t appear to be getting larger.

          2. Matthew Simmons Avatar

            I’d have to see the lid/bubbling to have better judgment of what is going on. If you can post a picture, I can try to point you in a direction.

          3. donna payne Avatar

            i’m having to back wash ny pump every 4 hrs or its stops pumping what could be the problem

          4. Matthew Simmons Avatar

            Do you have a sand or de filter? Do you have algae, or working on clearing up your pool? If you have sand, how old is the sand? I have more questions but this is a good start.

            We also have this guide: How to Reduce High Pressure in Your Pool System

    2.  Avatar

      Hi what part is Supposed to suck the water out inside the pool

      1. Matthew Simmons Avatar

        Do you mean the skimmer or the main drain?

    3. Jeb Avatar

      In my experience if pump basket is not full of water and flow is poor u may have a clogged impellar..

  10. Vee Avatar

    Can taking my filter out and cleaning it off while pump is on, cause cloudiness in my pool? We have tried EVERYTHING…for clear water again and still get a cloudy pool. We have a 13x33in upground pool. I noticed when my husband took the filter out (while pump was on) he put it back and all the stuff shot back out. I told him well that could be our problem???

    1. Matthew Simmons Avatar

      When was the last time you had you water tested?

      Also, have you used floc and vac? That should pull all the gritty particles out of your pool water.

      1. Tereza Avatar

        Hi, I have set up new Bestway damd filtration and missed the part, that must be filled up with water and accidently put it straight way for filtration. It just made big noise and stop immediately. I am wandering it run dry.whay can I do with it now?
        Thanks

        1. Matthew Simmons Avatar

          Install it correctly, see if it works. If the unit is broken then you can see if the dealer will replace it or if you need to purchase a replacement.

      2. AK Avatar

        The same thing happened to me. It was actually around the time we applied floc. We finished pouring the floc and ran the pump on filter all night to see if it would work. This morning we backwashed, but it’s still the same. It looks as if there was a lot of sand around the edges of the pool and the water is really cloudy. I set up my Dolphin to vacuum the pool, hopefully it’ll at least get rid of the sandy walls 😞.

        1. Megyn Avatar

          I have found when I put flocc in && run the filter on “recirculate” for 2 hours then turn everything off for 48 hours my pool has never been more blue && every single thing sunk to the bottom. Vacuumed to waste && I repeated a couple times cause the house I just moved into the pool was AWFUL

          1. Kevin Avatar

            How green was your pool water before?
            I’ve been at it for 6 days now and I cannot see down 4 inches looks like a lake water. 4 gallons of liquid chlorine didnt do a thing.

    2. TSC Avatar

      System needs to be put on service. That shuts the system down. You will be able to hear water leaving filter as you loosen top to get to actual filter. Unscrew top slowly and when you take top off, filter lifts out for easy cleaning with a hose. Reverse what you did and push service button once, if system doesn’t start, push again and it should start

    3. Jeb Avatar

      Never remove filter while pump is running, filter sediment in filter tank will return to pool if u do. Clean filter drain tank..

    4. Dave Avatar

      Why would you do that. Simple to unplug for 1 minute and replace before starting again. That is just pure laziness

      1. Larry Bowman Avatar

        helpful comment. more please

    5.  Avatar

      You need to vacuum your pool to waste. Vacuum so the water and algae vacuum out of the pool. You will lose a little water but that’s how you do it.

Leave a Reply

Your email address will not be published. Required fields are marked *