Pump impeller change

May 16, 2018
5
AVON
#1
I just replaced my pump motor, 3/4" H.P. Century, 56Y frame, and I also ordered new seals and a new impeller. The OEM part # on the impeller is Pentair 073127 and that is what I ordered. When I went to install it, I noticed the new impeller is slightly larger than the old one. I went ahead and installed it since I wanted to get the pump going. Is this an issue or am I OK with a larger impeller ? I have noticed that my in-floor pop-ups are not working correctly, but that could be the control head. It has failed before and seems to have about a 3-4 year life span.

Thanks for any advice.
 
May 16, 2018
5
AVON
#3
:wave: Welcome to TFP Bdarnell

Was it a 3/4 hp pump you replaced and was there a p/n on the old impeller ??
Well, what do you know. The old part # is 073126, not 073127 like the manual says. Good call.

Either the wrong impeller was installed at Pentair or the manual is wrong. Either way, the impeller I have on there now is what the chart in the manual calls out - 073127 for a 3/4 HP Whisper Flow pump.

Yes it was a 3/4 swap. Like for like.
 

Kiss4aFrog

LifeTime Supporter
TFP Guide
May 22, 2013
2,723
Hudson, WI
#4
Hopefully that works out in your favor with the bigger impeller moving more water and or saving some electricity. Wrong impeller can cost you in efficiency and $$.
 

JamesW

TFP Expert
Mar 2, 2011
12,844
#6
You can't upsize the impeller. You will overheat the motor. It might work for a while, but the motor won't last long.

The 073126 impeller needs a total hp of 0.95.

The 073127 impeller needs a total hp of 1.25.

Total hp is rated hp x sf (label horsepower x service factor).

A 3/4 hp motor is ok for a 073127 impeller if the service factor is 1.67.

The 073126 Impeller goes to a WF-2,
WF-23 or a WFE-2.

The 073127 impeller goes to a WFE-3,
WFE-24, WF-3 or a WF-24.

The WF-23 is listed as a 3/4 hp pump with a 1.24 s.f for a total of 0.95 hp and takes a 073126 impeller. This is considered to be an up rated pump. This is probably what you have.

The WFE-3 is listed as a 3/4 hp pump with a 1.67 s.f for a total of 1.25 hp and takes a 073127 impeller. This is considered to be a full rated pump.

So, there are 2 different 3/4 hp pumps that are really not the same thing, which is confusing.

What is the pump model number?

What is the service factor for the new motor?