Part # B859
Warranty 1 Year
Manufacturer Code B2859
Dimensions 14" L x 8" W x 6.5" D
Century 2.0 HP Pool Pump Motor – B2859
Single Speed | 56Y Square Flange | Threaded Shaft
✅ Features & Benefits
✅ Genuine Century (formerly A.O. Smith) replacement motor
✅ Horsepower: 2.0 HP full-rated
✅ RPM: 3450 single speed
✅ Voltage: 230/115V | Amps: 11.2 (230V) / 22.4 (115V)
✅ Service Factor: 1.10 | Total HP: 2.2
✅ Frame: 56Y square flange | Shaft: Threaded
✅ Rugged switchless design with ODP (Open Drip-Proof) enclosure
✅ Compatible with premium inground pool pump housings from multiple brands
➡️ Reliable High-Performance Motor Replacement
➡️ The Century B2859 motor delivers power, durability, and OEM-fit performance, making it a trusted upgrade for WhisperFlo, Challenger, Pinnacle, Max-E-Glas, and other premium pool pump models.
✅ Commonly Used On
Pentair: WhisperFlo (WF-28), Challenger, Pinnacle, Anthony AR2
Sta-Rite: Max-E-Glas, Max-E-Glas II, Dura-Glas, Dura-Glas II, Dyna-Glas, Dyna-Max
Jandy: PlusHP PHPM2.0
⚠️ Tech Tips & Cautions
⚠️ Not compliant with California or New York Title 20 efficiency regulations
⚠️ Always confirm frame type (56Y square flange) and horsepower before ordering
⚠️ Replace shaft seal during motor installation to prevent leaks
⚠️ Verify correct wiring for 115V or 230V operation before powering on
⚠️ Disconnect power before servicing
✅ Title 20 Compliant Alternatives
For customers in California or New York, or anyone seeking energy-smart performance, consider:
Century V-Green 1.65 HP Variable Speed Motor – energy-efficient retrofit with programmable speeds
Century V-Green 2.7 HP Variable Speed Motor – higher output with regulatory compliance and long-term cost savings
What is Service Factor?
Reply
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.
Reply
Why do I need to purchase a new shaft seal?
Reply
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.
Reply
Why should I purchase a Tune Up Kit?
Reply
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.
Reply
Do you have a replacement form1.5 hp part 7 177476 20?
1081 pool pump duty mount horizontal. What
If so what else would I need and how $$?
JR Dobson
Reply
1 to 2 hrs
Screwdriver, Socket Set
1 0
The morning after a bad thunderstorm we noticed the pool was not running, so I figured the fuse went and left it. After three days (and wanting to use the pool the following weekend) I went to investigate. The motor was brumming and was extremely hot…..
First thought was change the capacitor, so ordered one on Amazon….. at the same time I figured I should do something about the pump as it is nearly 10years old and runs 365 days a year.
Our pump is bolted to the ground and the back of the motor is around 1.5” - 2” from the fence, so while looking at the pump I couldn’t see if it was connected 115v or 230v (and was too lazy to measure) so I figured I would order a dual voltage pump to replace it,
Prices for a new 2hp Pentair Whisper flow dual voltage are between $1200-$1900 ($1900 was for an exact replacement). ……then i found the Inyopools website for motors.
I went through the website, found the motor I need. That linked to a video on how to replace the motor on my pump and I decided to order it. The video was clear and showed a step by step guide.
The capacitor I ordered from Amazon came the next day… I replaced it and got the old motor to run, but it was rough and extremely loud, but at least I was able to filter the water.
Three days later the motor arrived. Due to the space constraint I was not sure I would be able to do it without unbolting the whole unit and detaching the piping, but I gave it a go. with a little bit of wiggling I was able to get the old motor out.
Following the steps on the video I transferred over the parts from the old pump. I bought a tune up kit from Inyo, as they advised and replaced the shaft seal O-rings etc too.
As i knew I would have to wiggle the motor back in, I decided to superglue a few dots on the rubber seal to hold it in place (don’t know whether this was ok, but the glue said for rubber).
Anyway it took me a few minutes to wire it up due to a short cable and then about 10 minutes to get it back in. Tightened It up, turned it on and it worked. Much much quieter than my old motor.
If I had to give one tip, it would be to use a socket set for the wiring. It was a lot easier taken the wiring off the old motor than with a screwdriver.
Thanks Inyo. If I had not have seen the video, I might not have bought the motor. Needless to say, I am extremely happy I was able to do it myself and save $1000.
1 to 2 hrs
Screwdriver, Nut Drivers, Pliers, Wrench Set
1 3
$36.03
$312.70
$37.95
$594.78
The Most Helpful Review
44 6
(5 out of 5 stars) Pool Filter Motor
Reviewed By: DreamBigGoGreen from Bowie, Maryland ()
Pros: Customer service, shipping time, price and product
Cons: None that I can think of
Best of all is the wonderful customer service help provided by Inyopools. The product was here in the time specified and the price was considerably less than the 5 other companies I checked with first. The product was as specified and ordered and hasn't given me any problems to date. It was installed about a month ago.
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The Most Recent Reviews
(5 out of 5 stars)
Reviewed By: Inyo Customer ()
Great price. In for at least a year, quiet trouble free operation!
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1 0
(5 out of 5 stars) Century 2 HP pool motor....Powerful and Quiet
Reviewed By: Inyo Customer ()
After only about 6 years, the 1/5 HP motor on our Pentair pool pump started to whine! Obviously, it needed a bearing replaced but it was less trouble just swapping out the entire motor. After looking around for a new one, we found the Century from INYO Pools. We went up to a full 2 HP to increase water flow into our 12000 gallon inground pool. Delivery was fast and the new motor looked to be very well made and HEAV DUTY. After removing the old motor, the install went smoothly and in less than an hour with the help of a friend, we have the new motor up an running. No leaks, bone dry, etc. What surprised us both was how silent the motor was compared to the old Pentair motor! So quite, we almost think it is not running once you get a few feet away from it. LOTS of water flow and the inlet jets on the side of the pool now push water about 4 feet out. It also lowered our pump pressure from over 30 psi to just over 20. BIG improvement. The only issue we had with the install was when we removed the back electrical cover on the new motor. Apparently, it was on so tight that when we backed it out, it snapped off. The cover was able to be removed and put back on since it is a tight fit, but I will want to drill the hole out and replace the long screw/bolt. Other than that, the pump is working as it should and we hope it will serve us for at least as long as the original. All in all, I would not hesitate to recommend this motor due to its quality, quiet running and power.
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1 0
(5 out of 5 stars) Century 2.0 pool pump
Reviewed By: Inyo Customer ()
Very satisfied. Easy to install.
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(5 out of 5 stars) Motor replacement made easy!
Reviewed By: Inyo Customer ()
The motor came with excellent replacement instructions including the importance of replacing the mechanical seal. I did not order the seal initially, but after reading the instructions, I quickly ordered the seal to complete the job properly.
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(5 out of 5 stars) Top Quality pump motorbreplacement
Reviewed By: Inyo Customer ()
Replaced original 48 frame Class B insulation filter pump motor with this 56 frame class F motor...original only lasted 18 mos. Hoping the heavier duty replacement will perform well longer.
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1 0
(5 out of 5 stars) Replacement motor
Reviewed By: JrDIII from Overland Park, KS ()
Pros: See comment
Cons: UPS put a dent in it but function was not affected
Great product. All the installation materials and videos helped. Shipped and received as you said. Price was right.
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1 0
(4 out of 5 stars) Looks great
Reviewed By: Alice D. from Houston, texas ()
Pros: Very strong and easy to install
Cons: Black
The product looks great! Received it extremely fast. I haven't used it long enough to really give it a accurate rating
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