I may need to replace my pump motor (Pentair Whisperflo 1.5hp) and it seems like I can replace it with a cheaper Century motor that would cost me $162 versus about $220 for the Pentair. Any thoughts on these two motors? Are there any other motors out there worth considering?
Has anybody used a Century pump motor to replace a Pentair motor?
- Thread starter CajunGuy
- Start date
I don't think Pentair makes any motors, they re-sell a motor from someone else. Our 12 year old Whisperflo had an A. O. Smith motor on it, and I replaced it with one from "Century A.O. Smith", so I think there was a merger there. However I found there are several options even from within Century A.O. Smith's lineup varying in efficiency among other things. You will need to list model numbers of the motors you are looking at for anyone to be able to tell you much about them. My guess based on the prices I saw in my search is you are really looking at two different efficiency options and both are really Century A.O. Smith motors.
Looking that up, it is a 56Y frame and has a total hp of 1.65, so those are the things you need to match.
I would say your choices if you want to stay with a single speed are to replace it with the same motor (I see it for $162 on amazon). Or you could upgrade to the "E-Plus Energy Efficient" series B2841V1. I see that on sale now at for $199 at inyopools.com. I'm not quite sure how to calculate the payback time for the efficient option, but I am pretty sure it would pay for itself in electric cost savings over it's lifetime. I ended up going with a EE 2-speed motor to replace on our single speed Whisperflow, but haven't quite figured out how to take advantage of the low speed on a day to day basis yet since we don't have automation. I will be figuring that out this summer.
Searching around for Pentair motor replacements I think what you found in the $220 range was a Century BPA450V1? As far as I can tell that would also be considered energy efficient, but I don't know what the difference is compared to the B2841V1 if any other than case color, the specs all look the same to me. Maybe an expert here will jump in and clarify.
I would say your choices if you want to stay with a single speed are to replace it with the same motor (I see it for $162 on amazon). Or you could upgrade to the "E-Plus Energy Efficient" series B2841V1. I see that on sale now at for $199 at inyopools.com. I'm not quite sure how to calculate the payback time for the efficient option, but I am pretty sure it would pay for itself in electric cost savings over it's lifetime. I ended up going with a EE 2-speed motor to replace on our single speed Whisperflow, but haven't quite figured out how to take advantage of the low speed on a day to day basis yet since we don't have automation. I will be figuring that out this summer.
Searching around for Pentair motor replacements I think what you found in the $220 range was a Century BPA450V1? As far as I can tell that would also be considered energy efficient, but I don't know what the difference is compared to the B2841V1 if any other than case color, the specs all look the same to me. Maybe an expert here will jump in and clarify.
So it looks like the energy efficient Century B2841V1 shows a 1hp motor with a 1.65 service factor (not sure what this is?), but mine is a 1.5hp motor with a 1.10 SF...that doesn't seem like it would match up? I'm guessing the true hp is the listed hp x the SF to get the 1.65?
Correct, total HP is what needs to match up with your pump.
1.5HP *1.1 = 1.65 = 1HP * 1.65
From Pool School - Pump Basics
"Service factors determine how far over the rated or labeled HP the electric motor can be driven. Most pool pumps today are used at close to full load which is sometimes called braking HP, service factor HP, or operating HP and can be calculated by multiplying the labeled HP by the service factor. So a full rated 1 HP pump with a service factor of 1.5 would have a braking HP of 1.5 and would be identical to an up-rated 1.5 HP with a service factor of 1. Both pumps will have the same pumping capability and provide the same flow rates for a given plumbing system. This is one of the most confusing aspects of pump ratings."
To summarize I believe you have a WF-26 pump based on the motor that was on there. Based on the price you found, I would guess the pentair replacement motor is for the WFE-26, and thus would upgrade your pump to that efficiency level. That is why it is more expensive than the Century motor which isn't from the energy efficient series. I believe the B2841V1 would be equivalent to the Pentair replacement, and seems to be similar to the Pentair cost you mentioned, but it might be worth just getting the exact Pentiar part number for the WFE-26 replacement since it is almost the same price and would match color, etc.
1.5HP *1.1 = 1.65 = 1HP * 1.65
From Pool School - Pump Basics
"Service factors determine how far over the rated or labeled HP the electric motor can be driven. Most pool pumps today are used at close to full load which is sometimes called braking HP, service factor HP, or operating HP and can be calculated by multiplying the labeled HP by the service factor. So a full rated 1 HP pump with a service factor of 1.5 would have a braking HP of 1.5 and would be identical to an up-rated 1.5 HP with a service factor of 1. Both pumps will have the same pumping capability and provide the same flow rates for a given plumbing system. This is one of the most confusing aspects of pump ratings."
To summarize I believe you have a WF-26 pump based on the motor that was on there. Based on the price you found, I would guess the pentair replacement motor is for the WFE-26, and thus would upgrade your pump to that efficiency level. That is why it is more expensive than the Century motor which isn't from the energy efficient series. I believe the B2841V1 would be equivalent to the Pentair replacement, and seems to be similar to the Pentair cost you mentioned, but it might be worth just getting the exact Pentiar part number for the WFE-26 replacement since it is almost the same price and would match color, etc.