A.O. Smith Round Flange 1 1/2 HP Full Rate Motor (C1101, ST1152)



Part # ST1152

By A. O. Smith

  4.92 Average  



Part # ST1152

Dimensions 15.5" L x 7.5" W x 5.5" D

Alternate Part #'s 110284, 13870, 15236, 16055, 164566, 165113, 17318, 177026, 177032, 184950, 184950PJ, 186917, 19361, 1K048, 3K132, 52011, 5KCR49UN2088X, 6K878, 82772, 89361, 90118589, 90118761, 91715, 91727, B129, B139, B196, B709, B751, B796, C1101, C48L2N120, C48L2N120A2, C48L2N134HH, C48M2DB11A9, C48M2N107A2, C48M2N107A5, C48M2N110, C48M2N110A3, C48M2N110A4, C492, C56M2D107A1, C56M2N105, C56M2N110, C56M2N110A1, C56M2T61, C56M2T61A1, C56M2T61A2, C56M2U11A3, C56M2U11A6, C56M2U11A8, C56M2U4C3, CT115C, CT215CE, EB129, EB796, EST1152, JD15FL1, JD15FL1E, K48M2N106, K48M2N107A1, K48M2N107A2, K48M2N107A7, K48M2N110, K48M2N110C1, K48M2N111A2, K56M2N101A1, M-536DA, M-546DA, M546, MFK-19361, S88-175, SP1615Z1BBK, SP1615Z1BE, SP1615Z1BEE, ST1152, SW2562, V16055

Product Description

Voltage 115/230, Max Amps 115V = 19.4 230V = 9.7, Single Speed, Round Flange, RPM = 3450, Threaded Shaft, Frame = 56J Used on the following FULL RATE ENERGY EFFICIENT models: Hayward Super II Energy Efficient, Hayward Northstar Full Rate and Jacuzzi Magnum Full Rate pumps.

Motor Dimensions Motor Dimensions
Motor Image Motor Image

Product Specifications

Motor Name:
1.5 HP ST1152 Replacement Pool Motor
1.5 HP
3450 RPM
115/208 - 230 V
19.6/10.4 - 9.8 amp
Service Factor:
Total HP:
2.25 HP
Stock #:
Overload Protector:
Dimension Letter:
13 - 1/16 in.
Commonly Used On:
Hayward Max Flow, Hayward Super Pump, Hayward Super II, Hayward Northstar and Jacuzzi Magnum
NOT California Title 20 Compliant

?     Asked on 9/1/2018 by Albert

Is this the correct replacement motor? And what other parts do I need? I have a A.O. Smith Model: K48M2N110 (? Plate is worn/faded), SER: 8B02, HP ½ (? Plate is worn/faded), Volts: 115/230 (? Plate is worn/faded), RPM: 3450, AMPS: 19.4/9.7, HZ: unknown (Plate is worn/faded), SF: 1.33, FR: 56J, PH: 1, Thermally Protected: CET36WX (? Not sure first letter, worn plate), CODE: L, INSUL Class: B, ENCL: ?, TYPE: UAK, SP-1615-Z-1-BE Pool pump is Hayward SP3015EECR. Thank you for your help.

A     Answered on 9/3/2018 by InyoPools Product Specialist Lennox H.

Hi, Albert. Yes, this ST1152 is the correct replacement for MOD # K48M2N110. You will also need the Super II Pump Tune Up Kit - GOKIT2 or GOKIT2SALT

?     Asked on 8/23/2018 by

Is it dangerous to have ST1152 motor (full rate) with spx3010c impeller ?

A     Answered on 8/23/2018 by InyoPools Product Specialist Lennox H.

Hi. It is not dangerous to use the ST1152 motor with an SPX3010C impeller. 

?     Asked on 8/22/2018 by

What would happen when we use the ust1152 pump with spx3010c impeller ?

A     Answered on 8/22/2018 by InyoPools Product Specialist Lennox H.

Hi. Your pump will work as it should using the UST1152 motor with the SPX3010C impeller. 

?     Asked on 7/9/2018 by JACKIE


A     Answered on 7/9/2018 by InyoPools Product Specialist Hector F.

Yes, this would be the correct motor replacement for your ST1152. 

?     Asked on 6/5/2018 by Steve

I am replacing a Hayward SP3020EECP 1.5hp pump model K48M2N110. I am told the ST1152 is the correct replacement pump. My question- The original installation paperwork indicates the original pump may have been a 2hp pump (the 1.5hp is the second pump). This pump only runs water features (2 scuppers and 1 sheer descent). Is the 1.5hp ST1152 sufficient to run my water features? The furthest away water feature is about 50' from the pump. If this is the correct pump, what other products do I need?

A     Answered on 6/5/2018 by InyoPools Product Specialist Hector F.

So this motor model may say 1.5 horsepower on it but it is a full rated motor. What that means is that its actual total horsepower is 2.25. That very well could align with what you paperwork states.   

?     Asked on 5/29/2018 by

Will this motor replace a B129 that is currently installed on a Hayward SP3010X15? What else will I need to order to complete the installation? Thanks

A     Answered on 5/29/2018 by InyoPools Product Specialist Lennox H.

Hi. Yes, this ST1152 can be used as a replacement for the B129 motor. You will also need the Super II Pump Tune Up Kit - GOKIT2 or GOKIT2SALT

?     Asked on 5/25/2018 by Linda

I have a 4 year old RS Series RS1500 Hayward pool pump 1.5 HP and need to replace the motor. Which model A.O. Smith motor should I buy to replace the one I have?

A     Answered on 5/25/2018 by InyoPools Product Specialist Lennox H.

Hi, Linda. This ST1152 motor is the correct replacement for the RS1500 model pump. 

?     Asked on 5/9/2018 by Lyle Speer

I have a Magne Tek Part #8-177080-40, 1.5HP, Type CX, 3450 RPM, CodeF, Encl DP, Frame Y56Y, Form KJM, 1081 Pool Pump Mnt Horiz American Products #98710700, Model # 384484, Ser# 10966 Pool Pump. What is the Replacement, and the Shaft Seal?

A     Answered on 5/9/2018 by InyoPools Product Specialist Hector F.

The correct motor replacement will be the model B848 and if you click here you can view the parts diagram for your model pump. Key 2 has both the standard and saltwater version shaft seal but you can also purchase the GOKIT20 which has all of the seals and gaskets for your series pump. It uses the standard shaft seal. 

?     Asked on 6/11/2017 by Jeff

I have an aquatron II-6 pump and am replacing an ST1152. what gokit do I use?

A     Answered on 6/11/2017 by InyoPools Product Specialist Patrick P.

Hi Jeff you will require this AquaTron Seal Kit

?     Asked on 5/22/2017 by

I have a spa pump: Hayward 3015 X 20 EE. The correct (2HP) motor is too long to maneuver in place. It is located in a tight spot, so I assume the previous owner downsized the motor. I cannot read the old motor's label anymore, but the Impeller model # is SP 3015-C (which is a 1 1/2 impeller for a different pump) Will this motor be a valid replacement?

A     Answered on 5/28/2017 by InyoPools Product Specialist Lennox H.

Hi. This ST1152 motor is the correct replacement. If you need a smaller motor you can use the B129 motor. We recommend getting the GOKIT2, which has all the seals for that pump.

?     Asked on 5/17/2017 by Bob

I have a 1.5 HP Motor: Century Centurion (AO Smith) CAT # B229SE (Part# 184982) PR: Y56J motor. Will this replace my current motor?

A     Answered on 5/18/2017 by InyoPools Product Specialist Hector F.

No, this is not the correct motor replacement. It actually would be the model 5212X.

?     Asked on 5/10/2017 by GARY

I have a Hayward Super II Pump SP-3015AQ with an Century motor part #165111-21 3/4 pump. I need to replace the motor. I would like to go 1 1/2 HR with either the ST 1152 or the STS 1152 motor. What else will i need to complete this process.Thanks

A     Answered on 5/11/2017 by InyoPools Product Specialist Lennox H.

Hi, Gary. You will need the following parts. The ST1152 or STS1152 motor, Impeller - SPX3016C, Impeller Ring - SPX3021R, Diffuser - SPX3021B and Tune Up Kit - GOKIT2 or GOKIT2SALT.

?     Asked on 5/3/2017 by Mike

I have st1152 k48m2n110c1 and the bearings went out in it on my sp2607x10 Hayward pump and need to make sure I buy the correct motor because I will be installing it myself. Which is the correct motor and seal kit?

A     Answered on 5/4/2017 by InyoPools Product Specialist Scott W.

The correct replacement motor is the ST1152 and the seal kit is the GOKIT3, but just letting you know that your pump model says it is a 1HP Super Pump but you have a 1.5HP motor. Do you have a 1.5HP impeller to go with your 1.5HP motor?

?     Asked on 4/27/2017 by ROb

I have a 15 year old UST 1152 (motor model C48L2N134C1), should i replace this with the New UST1152 or upgrade to the ST1152.

A     Answered on 4/27/2017 by InyoPools Product Specialist Scott W.

I would go with the direct replacement UST1152 and replace the pump seals as well.

?     Asked on 4/19/2017 by John

I am replacing an AO Smith motor #K48M2N110. What motor should I use and what else do I need to buy? Thanks

A     Answered on 4/19/2017 by InyoPools Product Specialist Scott W.

Yes, the ST1152 is the correct replacement motor, if you have the pump model I can help with the shaft seal as well.

?     Asked on 3/15/2017 by JCampos

Will this replace my motor? Currently running a AO K63CXEYPY - 4766, 1HP, SF1.4 attached to a Hayward SP3010EEA2 (Z?). I would like to upgrade the HP to 1.5.

A     Answered on 3/16/2017 by InyoPools Product Specialist Stacey M.

Hello, The motor that matches this unit is an Energy Efficient A.O. Smith Round Flange 1 HP Full Rate Motor - CT1102, if you switch to a ST1152 you will have to change out your impeller and diffuser.  I highly recommend changing out your seals with Tune Up Kit Hayward Super II - GOKIT2.

?     Asked on 12/19/2016 by Mike

Hi INYO. I need to replace my pool pump motor. It is attached to a Hayward pump SP3015X20AZ (Super 2 pump?) driving a pool and spa. The current motor is a CENTURY UST1202 Total HP=2.20 Model K48M2N110C2. HP=2 FR 56J SF 1.1. I see on your website that you sell the UST1202, ST1212, and the ST1152. Which motor do you recommend and what are the differences? Thanks.

A     Answered on 12/19/2016 by InyoPools Product Specialist Adam Y.

Good morning Mike, You are looking for A.O. Smith 2 H.P Round Flange Up Rate Replacement Motor - UST1202 The seal kit you will need is Tune Up Kit Hayward Super II - GOKIT2 Unless you have a salt pool then you would need a gokit2salt.

?     Asked on 12/7/2016 by rick

hi, mine is a c48l2n134c1 pool pump, will this one work?

A     Answered on 12/7/2016 by InyoPools Product Specialist Scott W.

The direct replacement for that motor model number is the UST1152. You could replace it with the ST1152 but you might have to upgrade the impeller as well. For the motor replacement you will also need to replace the shaft seal as well. I can help you with that, just need to know the model of your pump.

?     Asked on 9/6/2016 by

Hi: Our pump model# sp2610x15. I don't remember the original gold motor's spec. other than it was 1.5hp. the current motor is a USTt1152. Question: can I replace it with a ST1152?

A     Answered on 9/16/2016 by InyoPools Product Specialist Megan C.

The SP2610x15 has a total HP rating of 1.5HP. The replacement motor is the UST1152 in use with a Tune-Up Kit. If you opt to replacing it with the A.O. Smith Round Flange 1 1/2 HP Full Rate Motor (C1101, ST1152) it is advised to change the impeller and the diffuser, to those that are recommended for the 1.5 Full Rate Motor ST1152. By increasing the size of the equipment you are increasing the the gallons per minute output from the pump. You will need to verify the design flow rate that your filter and plumbing is set for, before making your decision. If you only replace the motor using the ST1152 with the existing impeller and diffuser, you are only spending more money with no results.

?     Asked on 8/28/2016 by Larry Chek

We have a Hayward RS1500 pump with an AO Smith model # K48m2n110 1.5 hp motor. Our pool pump is moving water but putting off a burning smell. shuts down in the middle of a cycle. No impeller blockage. Assuming I need to replace my pump with your st1152, how does the motor separate from the impeller? They seem to be fused together with no obvious external screws. Also which tune up kit? Thanks!

A     Answered on 9/1/2016 by InyoPools Product Specialist Scott W.

That would be the correct replacement motor and the part numbers for the seals you will need for SPX1600Z2 and 5110-12A. As far as getting the impeller off, you will have to take the end cap off the back of the motor and hold the shaft with a channel lock so the shaft does not turn while you are trying to twist the impeller off.

?     Asked on 8/22/2016 by alex

are pumps ST1152 and UCT1152 interchangeable? Both look to be replacements for C48L2N134B1 Hayward super pump motors

A     Answered on 8/22/2016 by InyoPools Product Specialist Scott W.

It's gong to depend on if you have the UST1152 or the ST1152, the total horsepower is going to be the difference from 1.5HP to 2.25HP. So the UCT1152 will be good if you currently have to UST1152, unless you don't mind moving down in horsepower.

?     Asked on 8/18/2016 by

I have two different pumps. 1st pump I have is a AO Smith model # C48L2N134B1. this is the pool pump we had when we bought the house. This locked up and we bought a Hayward 1 1/2 horse but the model number we cant see. There is a number at the bottom which is SP1610Z1M. I would like the replacement motor only. Our pool is in ground and 40 x 20. Thank you

A     Answered on 8/18/2016 by InyoPools Product Specialist Stacey M.

Hello, A.O. Smith Round Flange 1 1/2 HP Full Rate Motor part number UST1152 is what you would want to replace the SP1610Z1M. When you click the link you will see your part number under Alternate Part numbers.

?     Asked on 8/9/2016 by Jennifer

This motor is listed as a replacement for my Leslie's Hydromax II pump. Can I replace this with the dual-speed A.O. Smith B977t? Also, which Go Kit do I need with this pump. Thanks.

A     Answered on 8/9/2016 by InyoPools Product Specialist Scott W.

Yes that dual speed would go with that pump. As far as the go kit, there isn't one with for that pump, but you should replace the shaft seal and housing gasket when you replace the motor.

?     Asked on 7/13/2016 by aaron

What housing and seal plate do I need for this ST1152 motor?

A     Answered on 7/13/2016 by InyoPools Product Specialist Alan M.

Hi Aaron, In order to match the correct parts, we would need to identify the pump that your motor attaches to. Please provide the make and model of your pump in order to better assist you. Thanks for your question.

?     Asked on 7/7/2016 by frank

Here is the model number for my pump motor, k48m2n111a2 . The unit is leaking can you advise me as to the seals that I should replace? Thank you

A     Answered on 7/12/2016 by InyoPools Product Specialist Lennox H.

Hi Frank, We will need to know the model number of the pump housing in order to locate the seals. If you do not have the pump model you can send use photos of the housing for identification.

?     Asked on 7/3/2016 by

I have a Jandy HHP 1.5 pump and I need to replace the motor on that. What are my choices? Also, is there a decibel rating on these motors? Thanx.

A     Answered on 7/6/2016 by InyoPools Product Specialist Lennox H.

Hi, The ST1152 or B129 can be used as a suitable replacement for the Jandy HHP15 pump. We do not have a decibel rating on these motor.

?     Asked on 5/28/2016 by

How old is this pump?

A     Answered on 5/28/2016 by InyoPools Product Specialist Alex V.

Hello, This motor is a brand new motor.

?     Asked on 5/17/2016 by

Does the motor come with everything you need to install it including gaskets?

A     Answered on 5/17/2016 by InyoPools Product Specialist Alan M.

The motor does not come with any parts, gaskets, o-rings, or seals. You will need to identify what pump manufacturer and model you have to determine which seals and o-rings correspond.

?     Asked on 5/9/2016 by David

What is the correct start capacitor for the AO Smith ST 1152 pump motor? The capacitor that failed is rated at 124-149 MFD and 165 VAC. Thanks.

A     Answered on 5/10/2016 by InyoPools Product Specialist Matt S.

The correct capacitor replacement for the ST1152 is the BC-124.

?     Asked on 10/1/2015 by

I have a Hayward RS1500 pool pump that the motor (K48m2n110) is going out on. I am unsure if this is the Hayward Super II motor but believe it is. It looks as though the replacement motor is the ST1152. I am looking for the go kit that I would need when replacing this motor.

A     Answered on 10/6/2015 by InyoPools Product Specialist Lennox H.

Hi, The A.O. Smith Round Flange 1 1/2 HP Full Rate Motor (C1101, ST1152) would be the correct motor for the Hayward RS1500 Pump, The  Hayward Super II Tune Up Kit (GOKIT2) is the correct gokit can can also be used on the Hayward RS1500 Pump.

?     Asked on 5/4/2015 by

Pump is on a timer. The motor will try to start, but only hum and either eventually automatically shut off (and then retry to start until it throws a breaker), if I re-set breaker, it will then at some point actually work until it is time for it to shut down. If you touch the pump motor while it is running it is VERY HOT!!!......should I just be getting a new motor?

A     Answered on 5/4/2015 by InyoPools Product Specialist Patrick P.

Yes based on what you are explaining I would suggest replacing your entire motor, especially since the motor is running so hot as this may have caused other damage to parts within the motor.

?     Asked on 5/4/2015 by

I run my pump year round about 8-12 hours per day using the 1.5 HP full rate motor....should the pump motor be lasting more than a year or 2?

A     Answered on 5/4/2015 by InyoPools Product Specialist Robert M.

The pump motors should last more than a year or two. Make sure you replace the seals when you replace the motor. Check out our guide on "How to Extend the Life of Your Swimming Pool Motor".

?     Asked on 3/29/2015 by Rick

How warm/hot to the touch should the motor feel after it has been running for a few hours...? The average outside air temp while the motor is running is 85 degrees F.

A     Answered on 3/30/2015 by InyoPools Product Specialist Andy O.

Rick, generally motors have a rating on them It will say AMB. It could, for example, say 50 Degress C, which means it will operate at 122 degrees F ABOVE the ambient temperature. Easily a motor can feel 200 degrees.

?     Asked on 5/2/2013 by Guest

My pump makes a loud high pitched screaming noise when running. The pump moves the water well but the noise is very loud. Would replacing the seals eliminate my noise problem?

A     Answered on 5/2/2013 by InyoPools Product Specialist Patrick P.

If the motor is making a loud, screeching noise while it's running, the bearings have likely failed. Replacing the seals alone will not resolve the issue. The motor and seals  should be replaced.

?     Asked on 1/19/2012 by Guest

I'm trying to replace the motor on my pool pump but all these numbers and abbreviations on the motor label are really confusing me. What do they mean?

A     Answered on 1/19/2012 by InyoPools Product Specialist Patrick P.

Replacing a pool pump motor is not as difficult as it seems. You can try looking here. If you need help figuring out what the information on your label means. If you are still having difficulty figuring it out you can call us at our toll free number or you can send us a photo of your motor label here.

?     Asked on 1/12/2012 by Guest

Why should I purchase a Tune Up Kit?

A     Answered on 1/12/2012 by InyoPools Product Specialist Patrick P.

A Tune Up Kit includes all of the essential replacement seals and gaskets for the pump. The seals and gaskets should be replaced when installing a new motor on your pump. New seals will prevent the pump from leaking water or losing the prime. A Tune Up Kit will protect your motor and ensure that the pump is working efficiently.

?     Asked on 1/12/2012 by Guest

Why do I need to purchase a new shaft seal?

A     Answered on 1/12/2012 by InyoPools Product Specialist Patrick P.

We strongly recommend replacing the shaft seal. The purpose of a shaft seal is to prevent water from running down the shaft of the motor and into the motor housing. Water will damage the bearings and cause the motor to fail. A new shaft seal should be installed whenever a motor is replaced. The motor manufacturer can deny the warranty if the motor fails to due to water damage from a faulty shaft seal. To find your shaft seal you will need to visit our Pool Pump Parts Page or the Spa Pump Parts Page and select your make and model.

?     Asked on 1/11/2012 by Guest

What is Service Factor?

A     Answered on 1/11/2012 by InyoPools Product Specialist Patrick P.

Service Factor(SF) is a multiplier that when multiplied by the horsepower of the motor indicates the total permissible horsepower loading that may be carried when the motor is operating at rated voltage and frequency. The most important thing to remember when replacing a motor is that the replacement motor's horsepower times its service factor must be equal to or greater than the original motor's horsepower times its service factor. The Service Factor rating can be found on the motor label. See Step 4 of our How to Read a Pool Motor Label guide.


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