By Century Motors



Part # UST1252

Warranty 1 Year

Dimensions 16" L x 8.5" W x 6.5" D

Alternate Part #'s 12020, 164135, 177022, 184951, 5KCR39UN6181X, 90118597, B231, B231SE, C1149, EB231, JH25UP1, K48N2N106, K48N2N106A1, K48N2N106A3, K48N2N106A9, K48N2N106C2, K48N2N113A6, SP1620Z1M, SP1620Z1MBK, UST1252, V12020, _UST1252, AOS-60-5243, CRMUST1252

Product Description

Voltage 230, Max Amps 230V = 11.2, Single Speed, Round Flange, RPM = 3450, Threaded Shaft, Frame = 56J Used on the following models: Hayward Max Flow, Hayward Super Pump, Hayward Super II, Hayward Northstar and Jacuzzi Magnum pumps.

Note: NOT California Title 20 Compliant. 

Dual Speed Option (NOT California Title 20 Compliant):

  • Dual Speed - B2979
  • Dual Speed - Hayward 2.5 HP Dual Speed Up Rate Motor - SPX1620Z2M
Motor Dimensions Motor Dimensions
Motor Image Motor Image

Product Specifications

2.5 HP
208 - 230 V
12.6/11.4 amp
Service Factor:
Total HP:
2.65 HP
Century (A.O. Smith)
3450 RPM
Commonly Used On:
Hayward Max Flow, Hayward Super Pump, Hayward Super II, Hayward Northstar and Jacuzzi Magnum

?     Asked on 7/14/2015by Ken

I have a 2 year-old UST1252 motor. I believe the start capacitor is failing - perhaps the run capacitor as well. The pump generally does not start (hums and then shuts down and/or breaker trips) the first time after sitting for a while. Flow seems good once it runs and the impeller seems to move freely (I have only reached in through strainer side, have not removed the pump (yet). All that said, can you tell me the size/ratings for the capacitors? Thanks! Ken

A  Answered on 7/16/2015 by InyoPools Product Specialist Lennox H.

Hi Ken, The A.O. Smith (UST1252) uses a Run Capacitor 30 MFD 370V (5VR0303) and Start Capacitor 36-43 MFD 120V  (BC-36).

?     Asked on 5/30/2016by Mike

I am looking to replace a pool motor UST 1252. Found in on your webpage along with tune-up kit. I was having pump leak problems at the seam between pump and main housing. Thinking of replacing at same time. Do you have a complete kit or only parts ?

A  Answered on 5/30/2016 by InyoPools Product Specialist Patrick P.

Hi Mike, we may have a kit but we would need to know the make and model of your pump. This should be something like Hayward Super Pump, Hayward Super II, Jacuzzi Magnum, etc.. Could you please email back with your pump details.

?     Asked on 5/8/2018by Ken

I have a UST 1252 motor connected to a Hayward Super II Pump. This motor is about 2 years old. It has begun to leak around the top of the seal between the motor and pump. I did replace the seal using your GO kit, but it made no difference. Cleaned the surfaces real well and the bolts are tight. It is a fair amount of leakage and definitely from top area, not the bottom. Suggestions/causes? Thanks: Ken

A  Answered on 5/8/2018 by InyoPools Product Specialist Hector F.

The Super 2 series has been known to get leaks at the bolts where the housing meets the motor. The bolt ports are known to separate from the housings. If that is the case then you can use the pump housing repair tap set part number 5110-22.

?     Asked on 5/8/2018by Ken

Hi, again: Related to the question about the leakage below. The inserts appear to be fully seated, and the leakage appears come from mostly the very top center area - between two bolts. Any other possibilities? The pump itself is about 11 years old, but not sure what would have caused it to start leaking suddenly. Thank you; Ken

A  Answered on 5/8/2018 by InyoPools Product Specialist Hector F.

If the seals have been replaced and lubed then the only other possibilities will be those bolt inserts or the housing has been warped to the point that they do not seal flush with one another. 

?     Asked on 5/30/2018by john

hi, i have a in ground pool about 38000 gallons i am using a haywood pump 1 hp the water flow is horrible. I can not turn on all jets (7) 2 floor-3 on the wall-2 at the steps-not enough pressure to push things to the skimmers. I want to upgrade to a 2.5 hp thinking it would be better but i noticed the rpms are the same what are your thoughts.

A  Answered on 6/9/2018 by InyoPools Product Specialist Alex V.

John, Any single speed pump will have the same rpms (3450). If you want to increase the horse power, you need to make sure that your filter and plumbing can handle the increased flow. 


Est. Repair Time

Less than 1 hr

Tools Needed

Screwdriver, Pliers, Socket Set, Adjustable Wrench

Failed super pump motor

Written on 9/30/2020 by Guest

Remove 4 exterior Motor to pump bolts
Remove next 4 bolts on bezel
Loosen rear metal cover screws
Remove impeller by securing the driveshaft nut and turning the impeller
Remove next two covers attached to motor
Turn off breakers
Remove electrical
Replace gaskets, seals and impeller spring
Reassemble in reverse with new motor

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 (Average 4.75  out of 5 stars)
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