How to Read a Century Pool Motor Label


  3.59 out of 5 stars on 17 ratings
(Click on a star to add your rating)

When replacing a dead Century pool pump motor the motor label can appear to be jumble of numbers and letters. This "How to" will guide you through which information is useful in your replacement pump motor search. We also provide tips on essential parts that should be replaced when installing a new pump motor.

Click Here to Find Your Replacement Pool Pump Motor 


Step by Step


Step 1

Tools you may need: 1. A cloth and cleaning solution, this is needed to remove any dirt or grime causing your pump motor label to be unreadable 2. A Shaft Seal or GOKIT when replacing your motor. Working seals and gaskets are vital to the health of your pool pump. A malfunctioning shaft seal will cause water from the pump to leak into your electrical motor causing it to fail prematurely. A GOKIT includes the complete set of your pumps gasket's and O-rings, including the shaft seal.

Click Here to Find Your Replacement Pool Pump Motor

Click Here to Find Your Pump's Shaft Seal & Gasket Kit 

Step 2

When tracking down a Century replacement motor there are two main markings on the label that can identify a match with a few keystrokes. These are the Catalog (CAT) or Part number. The catalog number is generally listed in the upper left of the label. Century’s CAT number format varies from pump to pump. For example a Pentair pump Century motor may contain a CAT number formatted like B2853 or BN24, where as a Sta-Rite pump motor is formatted as USQ1102R or SQ1202R. If your motor label contains any of these variations a simple search in Inyo's search engine will find the exact motor match.

Step 3

The second of these quick searches is the part number. This number follows the format of a combination of 9 digits in the pattern of "x-xxxxxx-xx". To make this a searchable number first, you must remove the first set and third set of numbers, this will leave the middle six digits. These six digits are worth their weight in gold. If you input them into Inyo's search engine an exact match can be found.

Step 4

Without a CAT or Part number the task of identifying the correct motor becomes more challenging but still achievable.

Step 5

In the situation where the Part and CAT numbers are unreadable the next best option is to back trace the replacement through the Pump model number. The pump model number is located on a tag somewhere on the wet end of the pump usually near the outlet port.

Step 6

Let's use P6RA6E205L as a sample pump model number, if you input this into Inyo's search engine the result is the manufacturer, model, horsepower, and even the service factor category. From there you could click the results and follow a link to the parts breakdown to show a complete parts listing of the pump. If you require only a motor you can write down this information, click Pump Motors under our "Shop by Category" click through the make and model information to find your correct motor replacement.

Click Here to Find Your Replacement Pool Pump Motor

Step 7

A search for the numbers listed above will return with results that though they should be accurate will still need to be matched to your current motor. The information most necessary to confirm compatibility is Horsepower (HP), Service Factor (SF) and Frame (FR).

Step 8

The horsepower of your pump is the measure of power output generated by your motor. Similar to your car engine the higher the horse power the more it can move.

Step 9

The Service Factor of your pump is a somewhat complicated rating in how it actually affects your pump. A simple answer to "What is a service factor?" is that when the SF is multiplied with the HP your pump “True Horsepower” is the product. Service Factor is broken down into two categories Up Rated (1.27 and below) and Full Rated (1.30 and up). When selecting a replacement motor be sure that you are selecting a motor with the same HP in the same category of service factor.

Step 10

The Frame (FR) is how the flange of the pump and shaft side of the motor are configured. Most pool pumps have a frame of 48Y, 56Y, 56J or 56C. The "48" and "56" describe the diameter of the motor casing and the suffix letter is the shape of the flange. A "Y" frame is square, a "J" and "C" are round flanges. When confirming a replacement motor's compatibility be certain that the Frame does match or it will not bolt on to your pump housing.

Step 11

Other information that is on the tag that is not essential to locating a motor match but still good to know are Volts, Amps, and Frame. Volts - Pool pumps normally have a setting of 115v, 230v or 115/230 dual voltage. Tip: Dual voltage motors are set to 230v from the factory so if you plan on using it for the lesser voltage is sure to switch this setting during installation or you may damage your motor. Amps - this is the power consumption of your motor, the higher the amps the higher the electric bill. Your specific pump may have an Energy Efficient motor available as a replacement. Check our Pump Motor section. Time - Pool pump motors are universally rated a CONT (continuous duty). Meaning they run constantly without needing to be shut off RPM - This stands for Revolutions Per Minute, single speed pumps run at 3450 rpm with dual speeds running at 3450 on high and 1725 on low.

Step 12

If by chance any of the above information on the pump is unreadable you may have to do some real digging to find a replacement motor. Read our, "How to identify your Pool Motor without the label guide, this will walk you through which parts have the information necessary to track down a replacement.

Click Here to Find Your Replacement Pool Pump Motor

Click Here to Find Your Pump's Shaft Seal & Gasket Kit 


(41 to 69 of 69)

 Posted: 3/7/2018 

Jim - Generally if you have four wire coming into a 220V pump, you would attach the two hot wires to L1 and L2, attach the ground wire to ground and cap off the extra neutral wire. I'm assuming that eh control unit has a neutral wire to provide the option of wiring to a 120V motor. Did your old control unit have 4 wires and were they attached as stated above?

 Posted: 3/3/2018 

I have an older Magnetek pump 1081/1795. The pump works fine; however I have to replace my control unit. The control unit is setup for a 4 wire connector, the pump is 3 wire. Do I simply forget about the neutral wire and wire in my 2 hot leads and the ground?

InyoPools Product Specialist  Posted: 8/5/2017 

Bob - This is not a concern. Tristar is the name of the pump. It generally uses Century (A.O. Smith) motors.

 Posted: 8/5/2017 

I paid for a Tristar motor and got a
Century motor. Should I be concerned?


InyoPools Product Specialist  Posted: 3/23/2017 

anonymous (warranty) - If you bought the motor from us, we will have your order and warranty information. Please give us a call at 877-372-6038 and one of our service reps will be glad to help you.

Anonymous  Posted: 3/23/2017 

I purchased a Century pool pump motor from you six months ago and it is making a high pitched noise, possibly a bearing issue. I cannot locate a warranty contact for them. Is this who I should be calling and do you have the contact information?

InyoPools Product Specialist  Posted: 8/15/2016 

robbieboy - Give us a call at 877-372-6038. We should be able to identify the bearings for your particular motor. You can use several types of motors to replace your current one. The main rule is that the motors' True HP must match. Look at step 9. True HP is the product of HP and SF. If you put in a motor that has less or more THP, you also might have to replace the pump's impeller and diffuser.

 Posted: 8/15/2016 

hi i have a century laser spa motor and it is knackered i think the bearings have gone how do i know what type of bearings to get? and worst case scenario can i just buy another motor? and if i do has it gotta be that exact type?

InyoPools Product Specialist  Posted: 8/10/2016 

harry - There has to be enough room behind the motor to pull it out from the pump housing. If not, you will have to cut the pump out of the piping to service it. Add unions when you replace the pump so that it will be easier in the future to remove the pump. See our guide on "How To Replace the Motor on Your Pool Pump".

 Posted: 8/9/2016 

how do I remove the pump from the motor? I have to change the motor but I do not know how to remove the pump. it is very tight is there a special way of doing it? please advise . thank you harry

InyoPools Product Specialist  Posted: 8/6/2016 

Pete - Your Magnetek Century Centurion motor, 10-186237-01 is a 2 HP FULL rated motor. Here is the link to that motor, 2 HP Standard Motor - Full Rate (B748, B2748). Note, this motor has an effective HP of 2.6 HP since it has a Service Factor of 1.3. Effective or Total HP (THP) is determined by multiplying the listed HP by the motor's SF. For more information, see our guide on "How To Understand True Pump Horsepower - Up Rated vs Full Rated".

 Posted: 8/4/2016 

I have a Magnetek Century Centurion part no. 10-186237-01 Serial no. B87-20 Can you please help in identifying the HP on the motor?

InyoPools Product Specialist  Posted: 8/2/2016 

manufacture date - The manufacturer date of a pump is usually coded in the unique serial number attached to the pump. You would have to contact the manufacturer to have them decode the number.

Anonymous  Posted: 7/31/2016 

How do you find the manufactur date on the pump?

InyoPools Product Specialist  Posted: 7/11/2016 

Magnetek motor - According to our motor manufacturer reps: "There is no aftermarket replacement for this motor. This is a 4-pole special build for the OEM. Would need to go back thru the OEM for replacement".

Anonymous  Posted: 7/4/2016 

I have a Magnetek motor that runs a water feature. Part number 8-184344-21. It has a separate tag stating that it's a specially designed motor. It has no HP rating or RPM rating. The frame is Y56Y,amps 4.8/9.6, volts 230/115 "HELP"

InyoPools Product Specialist  Posted: 3/30/2016 

MAINTENANCE BROWN - Check that you have 220V coming into your pump's motor. Sounds like you may be trying to run on 115V.

 Posted: 3/30/2016 


InyoPools Product Specialist  Posted: 1/24/2016 

Oki - If by "capacity" you mean the pump's ability to move water, you need to determine what Gallons per Minute (GPM) the pump will deliver. This starts with HP but then you have to estimate what resistance to water flow, or head, your pool system has. A given pump in a simple pool system with low resistance could deliver 65 GPM but with higher resistance it might only deliver 40 GPM. To determine how to estimate head, see our guide on "How to Size a Pool Pump for Your In-Ground Pool."

 Posted: 1/20/2016 

how do we know about the capacity?

InyoPools Product Specialist  Posted: 5/31/2015 

Mike - These Century (A.O.Smith) motors are used in most pool pumps manufactured and are generally very reliable. Most people get 5-10 years out of them. If you are experiencing this kind of turnover on your motors, I would look to the conditions in which they are operating. If your motors typically run very hot there are several possible factors that would make a motor degrade faster. See our guide on "How To Troubleshoot a Pool Pump Motor - Motor Overheated".

 Posted: 5/29/2015 

My pool is 5 years old and I am now replacing the Century pump for the second time. 3 motors in 5 years. Are these motors that unreliable ???

InyoPools Product Specialist  Posted: 4/26/2015 

pump housing - Unfortunately, the motor label only provides information on the pump's motor and not the pump housing. That motor is used with a number of pump models and manufactures. We need to identify the pump housing itself. We can sometimes do this through the part numbers stamped in some of the housing parts like the strainer cover. Please give one of our service reps a call at 877-372-6038 and they will help you id this pump housing.

Anonymous  Posted: 4/25/2015 

My pool pump is a Century Centurion CAT B748, FR Y56Y. I have additional numbers from the label if needed. I am trying to find information on the housing and filter basket that the pump fits into. The housing on my pump is cracked and sprays water when the pump is turned on. Can that be replaced without replacing the entire pump? I would like to compare the cost of replacing only that part or replacing the whole pump. Thank you.

InyoPools Product Specialist  Posted: 4/4/2014 

Texascat – Most people don’t try to replace a motor’s bearings because it takes special tools. You could take the motor into a local motor repair store but that sometimes costs as much as buying a new motor.

 Posted: 4/2/2014 

My 3/4hp pump is making a loud noise all the time it is running. I believe it is the bearings. I don't have the tools to replace the bearings . Help me

 Posted: 9/16/2013 

Can I send a picture of my pump "sticker"? The motor needs replacing and my sticker looks nothing like what you have is possible that the pump is almost 15 years old.

InyoPools Product Specialist  Posted: 10/18/2012 

Energy Consumption - If you run 8 hours instead of 24 hours, you will reduce your bill directly to 1/3 your current cost. You may be able to do this in the summer also, you just have to ensure that your flow is sufficient to run all the water in your pool through the filter in the 8 hours.

 Posted: 10/17/2012 

I have a 3/4 HP pool pump (Century Centurion) running all the time. RPM 3450. Volts 230, i think. Amps from label 'SF 6.0/12/0' ??
A friend suggests that I put the pump on a timer to run 8hrs day in the winter and save electical costs.
Question: How much will I save in electricity costs? The timer will cost $70
What's the down side?