7 Biggest Mistakes When Replacing a Pool Motor

I talk to thousands of customers each year about replacing their pool pump motors and the vast majority of our customers install the motors themselves without a hitch. However, occasionally we do encounter mistakes which are made when replacing your motor. So I decided to poll my fellow co-workers, manufacturers and vendors to come up with a list of the seven most common mistakes when replacing a pool motor. The results are in… Drum roll please…

#1 Replace Your Shaft Seal

The # 1 reason for motors going bad is corrosion to the motor due to shaft seal failure. We can’t emphasize enough the importance of replacing your shaft seal when you replace your pool motor. An important reason for replacing your shaft seal is that the warranty offered by the motor manufacturer is voided if there is seal failure. The manufacturer can spot a seal failure pretty easily as the face of the motor will get a scale build-up and often the shaft of the motor will completely seize. Typically if you use your old shaft seal, it will not line up properly with the new motor and you will have leakage. The good thing is that a shaft seal is pretty inexpensive (normally in the $15 range) and shaft seal installation is easy. We have made a video and step-by-step guide here showing how to install a shaft seal.

Another route you may consider is to get a tune-up kit, also known as a Go-kit. This kit consists of the $15 shaft seal, diffuser gasket, lid O-ring, housing gasket and lubricant for these O-rings. When you have the motor disassembled from your pool pump, it is an easy time to replace your O-rings and gaskets. Tune-up kits are normally in the $35 price range.

A few things to remember when replacing your shaft seal:

  • Don’t touch the ceramic portion of the seal with your fingers as the oils from your skin will break down the ceramic.
  • Remove both pieces of the old shaft seal as some customers have mistakenly tried to install the new seal over the top of the old seal.
  • Follow our video guide on How to install a shaft seal.

#2 Service Factor Service Factor, Service Factor

So you’re telling me a 1 HP motor is the same as a 1.5 HP motor? Well, in some cases this is correct. The topic of service factor is often an area of confusion, but can be fairly easily explained by understanding a few key concepts. The label on your current motor will have two very important pieces of information namely horsepower (HP) & service factor (SF).

If you multiply the horsepower rating times the service factor, you will determine your True Horsepower. So in our example below the 1 HP motor is the exact same as the 1.5 HP version of the motor.

1.0 HP X 1.65 SF = 1.65 True HP

1.5 HP X 1.1 SF = 1.65 True HP

High service factor motors are typically called Full Rate motors and low service factor motors are called Up Rate motors. Normally a Full Rate motor is equivalent to the next size HP in an Up rate model. Below is a handy-dandy chart illustrating this phenomenon.

Motor RatingHorse Power (HP)Service Factor (SF)True HP
Full Rate.751.51.13
Up Rate1.01.131.13
Full Rate1.01.651.65
Up Rate1.51.11.65
Full Rate1.51.52.25
Up Rate2.01.132.25
Full Rate2.01.32.6
Up Rate2.51.042.6

#3 Follow a Video Installation Guide

I know whenever I do any home repairs around my house I like to jump on Youtube to watch an expert perform the repair. This always seems to make the task go a little smoother. There are many videos online on how to replace a pool motor and these will help out tremendously during your installation. We would like to think our step-by-step motor installation guide and video is one of the best. We also cover how to remove your pool pump impeller, how to replace a shaft seal and how to wire a pool pump motor.

#4 Increasing or Decreasing Horsepower

On many occasions pool owners want to increase or decrease the horsepower of their motors. If you do decide to go this route then you will need to replace your impeller and possibly your diffuser.

Here are a few scenarios which are pretty common:

Switching to a larger HP motor – You currently have a 1 HP motor and you want to increase to a 1.5 HP motor. In this scenario if you stay with the 1 HP impeller you will only be getting the Gallons Per Minute (GPM) of a 1 HP pump, but you would be paying for the increased operational costs of running a 1.5 HP motor.

Switching to a smaller HP motor – You decide to downsize from a 1 HP motor to a .75 HP motor to save on electricity. If you do this without replacing your impeller to a .75 HP impeller then you will quickly burn out your new motor. This occurs because the .75 HP replacement motor will be overstressed by trying to output the water of the 1 HP impeller.

Sometimes when changing HP you will need to replace your diffuser. This is not always the case and varies according to pump model and HP. In most cases pool owners want to increase their HP, but more times than not the pump is already oversized for the pool. If you do increase your HP then the cost of operation for your pump will increase. A properly sized pool pump should be sized to turn your pool over in an eight hour time period. Here are a few considerations to take into account when increasing your HP:

  • Can your filter handle the increased output of water?
  • Can your plumbing handle the increased output?
  • Should you change your impeller?
  • How quickly will the new motor turn your pool over? (Quicker than eight hours may be overkill)

#5 Order the Correct Motor

Know your pump manufacturer & model

The easiest way to determine the motor you need is by determining the manufacturer and model of your pump. This will require that you inspect your pool equipment. Normally the manufacturer’s name and model of your pump can be found on the side of the pump housing near your strainer basket or on the motor label. I have listed some of the most common pump models here as I would estimate these account for 80% of the pumps on the market. These are: Hayward Super Pump, Hayward Super II, Hayward Power Flo, Pentair Whisperflo, Pentair Challenger, Sta-Rite Dura Glas, Sta-Rite Max-E-Glas & Jacuzzi Magnum. If you don’t see your pump listed here then visit our main pool motor page for a listing of all the replacement motors we carry.

Get the specifications from your motor label

If you are going to be heading out to your pool equipment for the manufacturer’s name and model of your pump then it would be helpful to jot down the following information from your motor label namely the HP, SF, Volts, Amps, RPMs, Cat #, Model #. This information will be on the label of the electric motor.

Armed with your pump manufacturer, model name and specs, it should be relatively easy to select your replacement motor from our main pool pump motor page. Also If you are able to obtain a model # from your motor then you can enter the model # directly into our search box and your motor should magically appear on our site.

Send us a photo, email, live chat or call

If you are having trouble tracking down the correct replacement motor for your pump then let us do it for you (this is what we get paid to do). So head on out to your pool pump with your smartphone or digital camera and snap a couple of photos of your motor label and pump and then send the photos to us at upload@inyopools.com. We will get back to you quickly with a motor recommendation. If you don’t want to send in photos then you can catch us on Live Chat or give us a call at 1-877-372-6038 and we would be happy to help.

#6 Go Energy Efficient?

Today there are some awesome energy efficient options for replacement pool motors. If you stay in an area of the country where energy costs are high then it definitely makes sense to consider an energy efficient motor. Traditionally the most expensive areas in the United States for electricity are California, Hawaii, Alaska (a huge pool state =)), New York and the Northeast. If you live in one of these areas, it makes sense to check out energy efficient options. There are a few different types of energy efficient motors: single speed motors, dual speed motors and variable speed motors.

Energy Efficient Single Speed Motors (33% Savings) – Single speed motors are the most common motors and are used on the majority of pools around the world. There are now energy efficient single speed motors which cost 20% – 30% less to operate than standard efficiency motors. Energy efficient single speed motors range from $185 – $350 depending on your horsepower.

Dual Speed Motors (58% Savings) – A step up in energy efficiency would be a dual speed motor. A dual speed motor can run at two speeds – a high speed (3450 RPM) and a low speed (1725 RPM). The two benefits of a dual speed motor are decreased operational cost and quietness during operation. The operational cost savings are determined by running your motor for a longer period of time each day at the low speed. Below are two examples which illustrate these savings.

Pool #1 – The Traditional Approach (Cost: $51.90 per month)

This 25,000 gallon pool has a normal 1.5 HP pool pump. It runs for eight hours per day. It pumps about 80 gallons per minute, which means that it circulates 38,400 gallons each day. The pump draws 9.0 amps at 240 volts. At a cost of 10 cents per kilowatt-hour, it translates to a cost of $1.73 per day or $51.90 per month to operate the pool.

Pool #2 – The Two-Speed Approach (Cost: 19.50 per month)

This 25,000 gallon pool has a two-speed 1.5 HP pool pump. It runs for 12 hours per day in low speed mode. In low speed mode it pumps about 40 gallons per minute which means that it circulates 28,800 gallons each day. Remember that the pool only needs to turn the water over once each day. The pump draws 2.25 amps at 240 volts in low speed mode. At a cost of 10 cents per kilowatt-hour, it translates to a cost of $0.65 per day or $19.50 per month to operate the pool.

The only time you really need to turn it to high speed is for backwashing or vacuuming, or if you need to increase the flow rate temporarily.

In this example you are moving less water, but the reality is that most pumps are oversized and as a result the pools are over-circulated. The two-speed pump provides just the circulation that your pool needs at a fraction of the cost.

Keeping the pool circulating for a longer period of time each day has a couple of advantages:

  • The longer periods of circulation will help to reduce the occurrence of algae.
  • If you have a salt system, you can run the system many more hours per day and get increased chlorine production if needed.

Dual speed motors range from $300 – $450 depending on your horsepower.

Variable Speed Motors (80% Savings) – Variable speed motors have gained widespread popularity over the past few years as they are the most energy efficient motors. Variable speed motors allow you to dial the motor into the exact RPM. You would typically select a range of 600 – 3450 RPMs. This allows for an almost infinite range of speeds for this motor.

The same principles for energy savings which were outlined in the dual speed motor example apply to variable speed motors, however, variable speed motors allow for far more flexibility. I personally think variable speed motors make a lot of sense if you live in area where energy is really expensive or if you have a pool set-up which requires more flexibility. On my pool I have quite a few water features and the variable speed motor is great because when I run my waterfall I can dial it in to a certain RPM. When I run my cleaner I use a different RPM, when I run my spa I also use a different RPM and when I run my filter pump I use yet another RPM.

Variable speed motors range from $490 – $700 depending on your horsepower.

#7 You Can Do This Yourself!

Remember you don’t need to pay hundreds of $$$ to a pool service company to replace your motor or pump. You can do this yourself and we have assisted thousands of homeowners with this process. If you follow these tips then you should have an easy time replacing your motor on your own without a professional. On average you are looking at $150 – $200 to replace your pool motor on your own versus $400 – $600 for a pool professional to do the job.

If you are not handy and don’t feel comfortable replacing your pool pump motor then you can still purchase the motor online and then call a local pool company to install the motor. Most customers just call around locally and say, “Hi! I need to get a price for the installation of a pool motor. I will be supplying the motor and shaft seal and I just need a price for the labor.” By taking this approach you can still save hundreds of $s. If you ever need any help with your pool equipment repairs, please let us know and we would be happy to assist.

105 thoughts on “7 Biggest Mistakes When Replacing a Pool Motor

  1. Good article.

    Many times (especially with legacy equipment) the information provide by the manufactures is limiter and what is available is wrong. Any ideas on how to address that eventuality?

    1. In those cases, the internet is your best friend as all hard copies of your manual are gone or the company that made your equipment has shut down. Luckily companies like Inyo have a back catalogue of old manuals in PDF form and resources for out of date equipment.

  2. Thanks for throwing pool guys under the bus.
    It’s all fun an games until joe homeowner screws it all up or worse, gets injured, by that electricity stuff, you know.
    Can’t believe I was actually enjoying the articles up until this.
    You should feel really good about yourself.
    I’m just glad it’s only me and about 10 other people who actually read this $#@%!!!!

    1. Hey Chuck, by no means were we advising against using a local pool technician in our blog. In fact we actually advise on how to find a good service tech in your area in another blog post titled, How to Find a Great Pool Guy. Our blog and how-to guides focuses on topics for the DIY-minded pool owner. With this mindset, we’ve been able to help thousands of pool owners over the years. Our advice in our how-to guides is always clear on the difficulty level of the process and caution users who are not comfortable with all aspects of the procedure to seek help from a professional pool service tech.

      Thanks for reading Chuck!

      1. chuck relax i found this info great and if someone is so stupid NOT to turn the electricity off before this they should not be allowed to handle sharp objects.you obviously know what your doing but a novice like me can at least get a ball park idea what to do and hopefully if it looks to much i would call someone like you ..

      2. Hey…a reply to chuck..i am a 59 yr old female..me and my roommate who is also a female..49 yrs old..replaced the Hayward pump that went out on my in ground pool..we were told that the pump was almost 450 bucks..thats NOT including installation…altogether almost 800 bucks..inyopools sold us the correct pump for 143.00..shipped it free..and after watching a great video..we replaced it ourselves..it is running great..i will do all of my business with them…tired of being ripped off by companies over charging…thanks for your help

        1. Hey…a reply to chuck..i am a 59 yr old female..me and my roommate who is also a female..49 yrs old..replaced the Hayward pump that went out on my in ground pool..we were told that the pump was almost 450 bucks..thats NOT including installation…altogether almost 800 bucks..inyopools sold us the correct pump for 143.00..shipped it free..and after watching a great video..we replaced it ourselves..it is running great..i will do all of my business with them…tired of being ripped off by companies over charging…thanks for your help my name is Lola clucas

        2. You said you paid $143 dollars for a pump? I would love to know where you got an inground pump for that price. You may have gotten a motor for that but a full inground pump that comes with a motor is $450. Hence you being told a pump costs $450. I just called inyopools and told them I wanted an entire pump for $150 and they told me I was crazy. They said we can sell you a motor for that. A motor is only part of a pump. In addition to the $143 you were charged for a pump I hope you got a viton shaft seal. If not, you will get more practice replacing that pump motor next year.

          1. What’s the matter, Steve? Irritated that the lady doesn’t even know what it’s called and still replaced the motor and saved herself a ton of money? I see idiot pool guys mess up all the time here in SW Florida. Drop parts in the sand and give them a cursory brush off with their hand, use the wrong lubricant, fail to add water to the pool so it runs dry and wrecks the seals. Then, they come back the next year like you said and replace the motor…again. They blame the weather or the motor or anything else. I was in the distributor when a pool guy brought in a new motor with bad bearings because he messed up the seal. He claimed the customer’s sprinklers did it. I replaced my motor 3 years ago. Had zero experience. Has run great ever since. Changing the motor is a piece of cake. I followed the instructions on this site and used US Seal lube.

      3. Hi Matthew, is it necessary to replace the pump when replacing the motor. I was told my pool motor is broke and need replaced. I was given two options: replacing the motor alone will be $500 and $75 service call, and motor and pump together at $950. What do you think of it? Thank you for your feedback.

    2. Please do consider that your response to the article could be considered throwing homeowners under the bus. There are many homeowners who have sufficient mechanical and electrical knowledge to install a new pool motor. Furthermore, much of the literature on this website reminds the owner that if they do not feel comfortable handling such a task, that they should seek the help of a professional.

    3. INYO is pretty informative in their installation instructions. Including a step to turn off power to the pump you are replacing. No offense but how many pool companies are nothing more than “joe homeowner” with a magnet on the side of their trucks and some chemicals in the back? Just saying.

      1. I would say (just a guess) the vast majority of pool guys are legit. But there is always those less than reputable technicians out there, doing pool service as a sidejob. The best route is to just do the homework on service companies before hiring them.

        1. Would you know of a web site that would buy pool motors at a heavily discounted price? I have 19 motors that I’ve stored in the garage for about 10 years. They are all new and unused but obviously would not have a warranty.

          1. I do not know of a site that would buy motors at that age. Your best bet would be to sell them directly on Craigslist or eBay. Be upfront in the listing about the age of the motors and that they are no longer covered by warranty.

          2. I could possibly be interested in purchasing a pool motor from you. Mine is sounding sick. That is why I am on this site researching pool motors. Please contact me by email. tamicude@aol.com

            Would you possibly have a 2 HP motor?

            Thank you for your time.

            Sincerely,
            Tami Cude

      2. Just want to give you my feelings on your comment. A homeowner with a magnet on the side of his truck would be a small business owner. Small business built this country and you are more likely to get a better price and more pleasant customer service from the small business owner then the chain store. The most knowledgeable people I have met in this industry are small business owners. I have been on both sides of the industry and I know the difference. So when the small business owner can replace your pump motor for 450.00 to 550.00 depending on HP the business that you seem to like so much will do the same job ” and probably send out a tech. That isn’t as experienced or knowledgeable as the small business owner and they will charge you 600.00 to 800.00. So if you like to over pay receive most Likely not as great customer service go right ahead. You know because we are nothing but just some guy with a magnet on my truck.

    4. Hey Chuck, it ain’t no brain surgery replacing a pool pump! You know, that dangerous electricity stuff….. they have those little doodads called circuit breakers that actually turn off the power when you flip them! I would rather replace the pump myself than wait for the “pool guy” to show up at his convenience, then charge me an arm and a leg for a simple repair !!! I am the 12th person who reads this blog!

    5. Chuck, you sound like a moron. I am the owner of a pool service company in Florida and a retired 25 year electrician out of Chicago and he said nothing badly about pool service techs. He merely stated that a homeowner, with the proper knowledge, can do this task by himself and lets face it…they can. It’s not rocket science.

    6. Hi Chuck, while, I understand “professional guys” like you need to make a living, you have to understand there’s plenty of homeowners with the qualifications to take care of themselves. I’m the kind of guy who drives guys like you nuts. I’m an engineer with an extremely wide variety of skills and I constantly add to them. In many or most cases, I’m more qualified and do better work than the “professional” and my costs of doing it myself are a fraction of the professional price. I can purchase the tools and do the work and still save lots of money and have a 1st quality job. I do hire some work out but at the end of the day, it’s my decision whether I hire a “professional” or take care of it myself. It’s simply what works out best for me, since I’m the customer. Fortunately, In the United States, we have the freedom to make our own decisions.

    7. dont be such a liberal. you using the electric part as a scar tactic to drum up more work. it is safe to wire in new pump with common seance.

    8. Pool guy here for 35 years and I found this article trying to source motors that have bearings which last more than 4-5 years, lately motors are crap, I remember the days when they’d last 15-20 years… no more! At any rate I have to agree with your comment, yes there are some capable people out there but having seen many homeowner motor installations 95% of the time it’s not done well… bond wire too left off, wires on the screws the wrong direction, crimps used on solid wire (a big no-no), the list goes on. Usually the liquidtight connector and conduit are in need of replacement from the UV light, we carry all that stuff and just do it when we change out a motor, also extend bonding wires and connect them properly with split bolts if there’s other gear and the wire is interrupted, it’s not code to put 2 wires into a lug atop the pump. Anyways, enough ranting, I don’t fix my car or even do my own house plumbing, I leave that to someone with more experience… in the end DIY pool repairs can cost you more in the long run.

  3. I’ve seen several places selling a commercial motor made by Baldor, they say is a perfect match for my burned up motor and it’s a better motor thats built in the U.S. do you know anything about these Motors? I’m also told they cost less.

    1. Mike, I have heard of the company Baldor, but I do not have any experience firsthand with their motors. After reading your question, I tried to dig up reviews of the 56J style motor that can is used on commercial and residential pools but there is not much insight from users.

    2. Baldor is an industry standard. if the nameplate hp and service factor S.f.are identical they are a good choice. remember the type of housing TEFC for outdoor should be same, do not use an ODP to replace a TEFC housed motor. NEMA frame size are typically standardized on every brand.

  4. pentair challenger 3/4 hp 1.27 SF
    Centurion Pac Fab pump

    27000gallon pool
    wanting energy efficient motor (if possible) without replacing entire pump

    suggestions?

    1. Hello JW, Your two best options for lowering energy consumption is going with either the ECM16SQU Variable Speed motor or a dual speed replacement. There are two dual speed motors that could work for you, either the B2980T (230 Volts) or the B2981T (115 Volts).Read this blog article too, to figure out which is best for your application: Variable Speed Pool Pump or Dual Speed… Which is Best for Me?

      Whichever motor you choose, always remember to rpelace the gaskets on the pump: Pentair Challenger Gasket Kit

  5. I have several homes that I rent out and each has a pool service tech to maintain the pools water condition. They do a fine job at what they do! I have discovered over the years that some tech’s are better at servicing the water conditions in the pools but lack experience when it comes to fixing pumps and motors simply because they don’t do it that often, so they always advise me to replace both when the motor or the pump is a problem. I either change them myself or have my maintenance crew replace hardware.
    In most cases it’s a motor that has gone bad so I have an inventory of equipment ready to be installed.

  6. I have a Pentair Challenger CFII-N1-1A/ 343233 pump 1HP / 1.25 SF
    Looking for more energy efficient and QUIETER option. I have read about a 2 GREEN 2 speed motor replacement as a possible option but am confused on which model would work for my pump. Do you have any suggestions on a 2 speed motor replacement without having to replace the whole pump? 1600 gallon kidney shaped pool with 1 skimmer, 1 waterfall, sand filter, salt water generator and robotic vacuum and 5 month pool season in which pump runs 10 hours a day with crystal clear water and good chlorine generation. plenty of water pressure from existing pump but very loud since it was brand new 4 years ago.

    1. Carla, Your Pentair Challenger 343233 is a 1 HP Uprated pump, so with a little math, that means your correct motor replacement is either the AO Smith 2-Green B981T or the B980T. Your choice between the two is determined on which voltage you are using for the installation.

      Your 1 HP uprated and the 2-Green’s 3/4 HP Full-rated equal the same total HP of 1.25, making them a drop-in replacement. Regarding the motor’s decibel level, it should be quieter than your old grody motor just based on age.

    2. I trimmed my impeller diameter 1/2″ on an old hayward pool pump, and reduced my pool amp motor draw from 11.5 amps to 8.8. Approx 20 Less. My problem was a overheating motor. had 12 gauge and 15 amp breaker, now it runs cooler and never trips breaker. head pressure loss was negligible . it just runs further over on pump curve, about 10% less flow.

  7. Variable speed is the only approach to take. Anything else will end up costing more in the long run. 2 speed motors are still wound motors, and in a lot of cases the low speed is not enough to circulate the pool.

  8. Currently my pool motor brand is US Motors. I have read reviews online and people were giving it bad rating. I want to replace it with a better brands. Is that possible?

    1. Eric,

      The most common pump motor brand o the market is Century/A.O. Smith, they are the standard for motors in the industry. Brand new pool pumps usually come equipped with a Century/A.O. Smith motor even if they are stamped with the Pump maker’s sticker. You really can’t go wrong with an A.O.

      1. Matthew, thanks for replying back. So it’s ok to replace it with another brand huh. My motor doesn’t work, it gave out two weeks ago. My pool hasn’t turned green yet. I need to replace it quick. Yes, I have heard of Century brand. One other question is if I purchase a new motor does it come with a seal/Washer?

        1. The motor does not come with the shaft seal. Replacement pump motors can be fitted to dozens of pump models, which in turn use various shaft seal types. To find the correct seal, you would need to know the make and model or model number of your pump housing.

          I can also find the correct replacement motor for you; what is the part, catalog, or model number your motor’s label?

          1. US Motors K63CXETM-4819. But I don’t want to use this brand anymore. It will break down in a year or less.

  9. Hi Matthew, I have a 2 hp Whisperflo with a 1.3 sf. I would like to increase 2 areas. #1 efficiency, as I live in so cal and electricity is at a premium, #2 water pressure in my spa. I already installed a blower but it doesn’t make up for water pressure. Any help will be appreciated.

    1. Is this a pool/spa combo or a spa only? Also is the original motor on the pump or is it a black replacement motor? I ask the latter because pool companies have been known to install a higher HP motor on a pump just because they don’t have the lower HP in stock. So your motor may say 2 HP, but the impeller inside the pump would be a1 or a 1.5.

      If it is a pool and spa combo, I suggest going with the AO Smith 2.7 HP V-Green. The V-green is a variable speed motor that will allow you to perform regular filtering at lower speeds to save money but allow you to kick up the HP to 2.7 for spa use.

  10. I have a pentair challenger 1.5 horsepower pump that has recently burned up. My basket and pump housing both had leaks in them and after a few weeks of the pump struggling to prime itself it finally burned up. I want to say my pool is 15,000 gallons. I need the whole pump/housing/basket combo. Is a 1.5 hp too much? Also what are my alternatives to the pentair challenger which is more than I want to spend. thanks.

    1. Matthew-good name.

      The Pentair Challenger has four types of 1.5 pumps; uprated and fullrated, then those two are given standard or energy efficient motors. I would need the model number of your pump housing to match your pump to a suitable replacement.

      Once we know what you have then we can figure out if you need to step it down or not.

  11. I bought a new variable speed pump. What is a good material for shimming the pump up in height about 3/4 of an inch. The new pumps inlet is closer to the ground.

      1. I wound up using 1 by 4 rough sawn plastic trim boards. I got the exact height by ripping it with a saw, and stacking two pieces on top of each other.

  12. Matthew,
    First off, I want to let you know how much I appreciate all your advice and tutorials on your website. Pool ownership is expensive enough without having to pay for a pool guy. With that said, I have a US Motor 1081 with a clearly stated THP of 2.25 (HP 1.5 & SF 1.47). Do y’all have a bolt up replacement for this motor along with a new shaft seal and gaskets?

    1. Thank you, Eric. To find the match for the motor, we need to know the model number of the motor or the Model number of the pump housing. The 1081 is on every pool pump motor, no matter the make and model.

        1. The Pentair SuperFlo uses a GOKIT78. And a heads up, that K63 number is another motor model number.

          For any future comments on this thread. If the model number you are looking at is on the motor label, then it is not the Pump model number you need.

  13. I am changing the 1hp motor of a SP2807X10 pump. The cuts are all original; the first rebuild. I can’t find the correct shaft seal, because the impeller (SP2607-C) shaft has two opposing cams, which prevents the impeller part of the seal to slide onto the shaft. The original impeller part of the seal has a detent/groove, which prevents the seal from spinning on the impeller shaft.
    Does anybody have an solution to my problem?

    1. That piece of metal you are seeing on the base of the impeller is likely a piece of the old shaft seal. That sleeve is the inner base of the old shaft seal’s spring side. Just pull it off with some pliers, and possibly with the aid of WD-40.

      impeller shaft seal

  14. Is it necessary to change the shaft seal if all you are replacing is the impeller? I have a Sta Rite Dura Glas and there was a lot of noise coming from the impeller/diffuser area. The noise has lessened but so has my return pressure. Pretty sure one or both are damaged and I am planning to replace them both. The motor is good. If I replace the impeller and don’t intend to break the motor loose do I need to pull the motor and replace the shaft seal anyway or can I put the spring loaded side of the existing shaft seal back onto the new impeller?

    1. The shaft seal is connected to the impeller stem, so no matter how you do it the shaft seal is coming out. Because a shaft seal is a relatively inexpensinve piece, I would install a new one. Your motor is fine now, but if you use the old shaft seal and it fails then you’ll have a whole new set of problems.

  15. I had to replace my pump recently from a Hayward super pump due to it squealing and then locking up. It cost me 400 and they replaced it with a century HTS110. Is there a difference? Why did it cost so much?

    1. Do you mean you replaced the motor? If so, 400 is definitely on the high side unless it was replacing it with a dual or variable speed. If they replaced the whole pump, 400 is a great price for the pump and labor.

  16. My motor just died and I had a technician out here that said it needed to be replaced. His replacement was for the U.S. Motors Emerson EB843 2HP Squared Single Speed Motor which retails for $400, and with labor would cost $600. Is there a comparable motor I can buy that is cheaper. I can hire a pool tech to install for $125. So I’m looking to save money on the motor. Any help is appreciated.

  17. Hi Matt,
    My Emerson 1081, 1 hp, 1.4 sf has just seized up. Should I replace with the same or is there a more efficient option?

  18. With a 1.5 hp motor, what AMP breaker does it require. I replaced the pump breaker with a 30 AMP and it blew the new motor up.

    1. If you look on the motor label, there should be an amp rating. A 1 HP motor usually has an amp draw between 12 and 16 amps. Do you have anything else on the breaker besides the motor?

  19. One thing not mentioned is installation of a “SLINGER” which is a loose washer on the motor shaft between the seal and motor bearing. This helps stop water from entering the front motor bearing.

  20. Can you run a 1.5HP variable speed pump at the equivalent of 1.0HP to replace a 1.0HP pump? I would think throttling back the RPM of a 1.5HP should give you the equivalent pumping of a 1.0HP, but I’m not quite sure how to calculate what RPM setting would be the equivalent. Should I just run it at 2/3 the max RPM and consider that the proper maximum for emulating a 1.0HP pump?

    1. This will depend on a few things; first is whether you are replacing the whole pump or just swapping in a variable speed motor. If only the motor is being replaced then the then max flowrate is going to top out at 1 HP with the same impeller.

      If switching the whole pump, the RPM is going to depend on the model you replace it with. Different pumps have different flow rates, but it is not something you will know until you install the pump and begin fiddling with the settings. Variable speeds involve some tinkering to make sure your RPMs are set for your application.

      1. That’s one more reason why I don’t want a variable speed! Adds more cost to have to call someone to make sure they are set correctly. Everyone I have called wants to install a $1400+ 3HP unit to replace my old 1 HP motor. Setting it too high could damage my filter.

  21. A friend of mine gave me a 2 horse power Hayward super II. He said it worked. I replaced my old 2 horse power jacuzzi jets only pump. I was told the old pump is not made any longer. I checked the new used pump to make sure it worked before putting it in and it seemed to work. I put it in and it runs but very little comes out of jets. It is a 2 speed pump. Could it be a bad pump or wrong speed? How do I tell the difference.

    1. Was your old pump a two-speed? If the old pump was a single and you did not change the wiring, you are likely running it on low speed. Did you follow the wiring directions on the side of the motor?

  22. Interesting read. Matthew you provide pretty good advice. I’ve been in the pool business in construction, service , service mgmt and now 20 years in wholesale distribution. I’m
    59. We sell to pool retail stores, pool builders and pool builders. We sell everything but the concrete or water. I read this entire pool motor blog. The reason INYO and others sell for less is mainly overhead and the fact that they are probably buying from the manufacturer and trying to provide a high level of service on the 10-20% GM (gross margin). The traditional method of supply is the pool service guy buys from the wholesaler like the one I work for (I actually started the company in the 70s) and so we have millions invested in inventory, extremely knowledgeable support staff and facilities located in two cities. We make a gross margin and the professional dealer makes a margin. So it’s going to cost more for the motor. By the time the pro guy adds up all the costs (I will not bore you with the compliance costs tabulation) its about a $126-$135 cost for him to put a motor on in his normal travel area. The V Green motor is awesome and Matthew is doing a pretty good job of trying to help, but like in whatever anyone does as a career/profession …. experience and integrity matters and costs more than those without it. There are probably a bunch of you tube videos out there for those determined to DIY , but there will always be circumstances that the pro installer knows because of experience and if he does it know he can ask the pro that he buys from. It’s like I can order paint from anyone if I am sure that I’m getting what I need or I can ask a Sherwin Williams or Benjamin Moore pro…and get the right thing. A good pool guy is like those guys. Replacing a motorvif you’ve not done it is “iffy”. When I worked retail we sold motors to pool owners and they messed up about half of them. We spend years getting them to bring in the motor with impeller on it and we installed the motor, seal, seal plate and made sure it was set for the correct voltage and about 10% of those got installed wrong and we sent out a service tech to get it right. Hope that helps … Matthew you are doing a good job trying to help but there is only so much you can do from afar. Please forgive any misspellings. Good luck everyone and by all means like several have said make sure that breaker is off.

  23. I live in north Florida and have an in-ground 10,000 gallon pool screened-in pool with solar panels to heat the pool when needed. My 1 hp motor is 5 years old and starting to fail again as I hear it getting louder like five years ago. I typically run the pool pump 8 hours a day in fall/winter and 12 hours pr day in spring/summer. I would like to purchase a high end replacement pump/motor this week. Last time (December 2013) I went to a local national pool store franchise and paid $329.63 for a “1 hp Motor, USA? 125, mech seal and seal plate seal” that included a $75 installation charge. Should I use them again? I have no interest in doing it myself. Thanks.

    1. Those prices are pretty steep for a single speed motor. I’m not sure which 1-hp motor you need but they generally range from $125 to $185. A pump gasket kit, which includes all the seals of the pump, costs about $37.95. There are plenty of technicians that will install the parts even if you did not get it through them.

      If you need help finding the correct motor replacement, take a look at the below video:

  24. Do your research I just replaced pool pump and seals etc. 165.00 bucks.grainger was the cheapest price for the motor..

  25. I need to replace my challenger pump system it is very old. I have a 1 1/2hp now and it looks like 209v 230v. I see the new ones that say 115v 230v. Can i use the 115v 230v system?

    1. You probably don’t have the pump wired for 208 voltage but you can test to verify. 208 is typically only used when you’re set up for 3-phase wiring and someone has split off a line. Normally, commercial sites would be the only ones with 3-phase electricity.

      If you are 230v you can replace the pump with one that is 115v/230v.

  26. hey this is for a spa but i have a flomaster 1.5 hp motor with a 1.0 sf with a bad impeller and a 1.65 hp wit a 1.0 sf motor that is bad can i use the 1.65 impeller on the good motor

      1. honesty i am not sure I think the 1.5 is a 48 frame and the 1.65 looks like the other one except there is a small hump on top with what looks like a small electric motor on the inside i will post a picture if i can
        they are two different motors as far as brands i will post the motor types as well thanks

        the 1.5 hp motor is a flomaster aqua flo fmcp pump now the impeller that was on it the factory 916 part number came back to a 1 hp impeller which i thought was weird the other motor is Watkins wave master 7000 jet pump 1.65 hp. I do think they are both 48 frame but i don’t know for sure

          1. one has the fr on the label and one does not the one that does is a x48y that is one Watkins motor the flomaster does not say

  27. Anyone have any idea how to figure out where the holes are inside the motor. Friend removed the place without marking it. Now we can’t figure out how to get the 4 long screws back on?

  28. Easier and a more sure fix to replace the whole pump/motor assembly than just the motor, especially for amateurs.

  29. Thank you for such an informational website! I think I just ruined my 1.5 horsepower. S F1.0 motor trying to open my pool. Local pool shop wants about 700 bucks. I found one locally through Craigslist. It’s a 1 horsepower with an SF of one. My original 1.5 ran on 220. This potential new one horsepower runs on 110. It would actually be much more convenient! Will I expect the same Performance Based on your article on this? Thank you again!

    1. If you use the 1 HP uprated on a pool pump that has a 1.5 HP uprated motor, you are going to kill the new motor as well. The 1.5 pump is going to have a larger impeller, that the smaller motor is going to have trouble spinning, causing it to overwork and eventually die. If you go down in HP< you will need to change the impeller, and possibly the diffuser to make the smaller motor work. We carry all the replacement pool pump motor you could ever need, and we show you how you can install it yourself. The job will be a lot less than your quoted $700.

  30. Hi! We hired an electrician to replace our pump motor only. He installed a US Motors brand which matches all specs on our old Hayward Motor. The 1 1/2hp Hayward has worked well for over 8 years and has always operated/propelled our Polaris side wall pool vacuum. The new 1 1/2 US Motor is not moving enough water through the system to operate the vacuum. It is about 1/2 of the water that was pumping through with our old Hayward motor. What would cause this reduction in water volume force and pressure. Water pressure gauge went from showing in 20’s down to 10 with the new motor.

      1. I checked all those items in the article. Is it possible that the US Motor brand just doesn’t operate as efficiently/strong as the original Hayward super pump motor? Thanks for your reply!

        1. Maybe. US motors are the lower cost replacements for a lot of the A.O. Smith – Century motors found on pool pumps. But it could also be an air leak issue.

          I would check to make sure you installed a motor with the correct Total HP.

    1. Hey Kay, I’d take a wild guess the motor was factory wired for 220v and you have 120v, that’d cause it to run slower and not pump proper water. I saw a few customers with pumps wired incorrectly for years! Electricians are notorious for not changing the voltage on pumps, in fact on my very own pool I had an electrician hook it up to 220 (I had it temporarily hooked up with an extension to run on 110) and he ruined my brand new motor by not making that change.

  31. I followed the look up replacement instructions on here to replace my AO Smith SP1610Z2MSC with a what was suggested which was a B2842. The shaft to the new motor is too big- won’t fit my impeller, etc.
    Why is this?

    1. Hello Tina – I did a search for the SP1610Z2MSC, and the correct motor replacements are round flange 56J motors like the STS1152 or the B975. The B2842 you have selected is a square flange 56Y which is not compatible with your pump housing. Regarding the motor shaft, the dimensions for the B2842 shows the threaded portion of the shaft is half an inch wide but the motor you require is only a 7/16″ threaded shaft.

      In short, get the correct motor and it should mount fine to the housing.

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