How to tell if I need a new pump, motor, or capacitor?

popechild

Member
Nov 23, 2015
11
Atlanta, GA
I've been reading threads trying to learn what I can but at this point feel like I just need to ask specifically about my situation. I have a pump motor that appears to be going bad. This morning when I walked outside I heard a loud hum type noise coming from the pump, then after about 10 seconds (before I could get to the pump area) it shut off. When I got to the pump, I noticed that the timer was on and power seemed fine (the timer and SWG were both operating) but the pump was completely silent and non-operational. I tried a few basic things like cycling the power at the breaker and checking for loose wires, as well as switching the timer on/off a couple of times. Never got a response so I left the timer turned off.

About 15 minutes later when I went out again to check for a model number, I tried turning on the timer again and it started making the same loud hum noise, but no water flow or other evidence of movement. After about 10-15 seconds I heard a click and it turned off again. Not sure if it hummed again because it'd been turned off for 15 minutes or if that was just a coincidence.

At this point, how should I proceed in determining if I need a new motor (my default suspicion) or an entirely new pump (I can't see any noticeable cracks or problems with the rest of the pump but I suspect it's relatively old - we moved in 2 years ago and I have no idea how long it was installed prior to that). Or how would I know if I'm lucky and only need a new capacitor?

If my assumption that I need a new motor (but not entirely new pump) is correct, this is the result I get when I try to search by the current motor's model number. Magnetek A.O. Smith 1 HP, 56Y Frame, Up-Rate Motor (B2853) - INYOPools.com

Does it look like the correct replacement? And do I need other parts like gaskets or seals beyond just the new motor? I've replaced heat pump blower and outdoor fan motors before, so the idea of replacing a motor isn't inherently scary to me, but I don't know what I don't know when it comes to pump motors. Thanks!

Pump: Pentair Superflo (350097 is the only number I see on the label)
Motor: Pentair 177474 (1.0 HP; 1.25 S.F. HP; 3450RPM; MaxAmps 7.1/14.2)
Filter: Hayward S-220T
 

niteshift38

Silver Supporter
Bronze Supporter
Jun 10, 2017
186
Hamburg/NY
Sounds like a bad capacitor. It turning off is a thermal guard built into the motor. To be more sure, you could try to spin the shaft with power disconnected to make sure it spins freely and that there is nothing binding anywhere. I'm not sure where the capacitor is located on that particular motor. Others on here may have had experience changing it. If you find it, the size of it should be printed on it. Good Luck

Just to add, does yours have the cylinder on the outside like the replacement you were looking at? If it is, then the capacitor will be under that cover. I am attaching 2 pictures of a good and bad capacitor (please note this was on an Air Conditioning unit, but the symptom should be the same)

Bad Cap.

Bad Cap.jpg

Good Cap
GoodNew Cap.jpg

The top will be bulging when it goes bad. Hope this helps!

I want to add to NEVER attempt opening, or working on a motor with the power cord plugged in !!!! I cannot emphasize this enough!!!

ALSO ---- Before trying to unplug and replace the capacitor, place a screw driver across the terminals to make sure that it is discharged completely (Think of a capacitor as I VERY big battery)
 
Last edited:

popechild

Member
Nov 23, 2015
11
Atlanta, GA
Thanks for the response. From what I can tell, the capacitor in that top access cover isn't bulging. It does appear rounded a bit, but I would think that's just the natural shape of it. If you still think it might be the capacitor I could try swapping one out though. It does seem like the pump motor will turn on (i.e. make that loud humming noise) when it's been sitting off for a while, so it does probably just shut down after 10-15 seconds when it realizes it's not actually turning.

There's a shaft access cover on the side I removed and I could turn the shaft from the end freely in either direction, but again, it doesn't actually turn during the loud hum, and nothing at all happens after that hum clicks off.

Does that help narrow anything down?

IMG_1135.jpg
 

niteshift38

Silver Supporter
Bronze Supporter
Jun 10, 2017
186
Hamburg/NY
Rounded is the same as bulging! It should be perfectly flat. I would start with that right off. Find a local place that repairs motors in your area and see if they have one in stock. If not, they may be able to point you to somewhere that does carry them (unsure if pool stores carry them). Think of replacing a capacitor as buying a lottery ticket for, usually under $20, and having 50/50 odds at winning. Just do not forget to use the screw driver to make sure it is discharged. Good Luck
 

Ted527

Well-known member
Jul 3, 2017
151
Moorestown NJ
Capacitor could be bad with absolutely no visible signs of swelling, no way to be sure without a tester.
Changing it is a cheap roll of the dice.
 

popechild

Member
Nov 23, 2015
11
Atlanta, GA
Thanks, folks. I removed the run capacitor and the bottom is (very) slightly rounded. I also used an Ohms meter and don't appear to be getting a charge through it, so I'm guessing the capacitor is indeed bad. I've ordered a replacement that should be here in a few days. Fingers crossed. Thanks again!
 

Fjvaughn

Well-known member
May 21, 2017
77
NJ
Pool Size
21000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Good call. I get most of my pool parts from Uncle Jeff.
 

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niteshift38

Silver Supporter
Bronze Supporter
Jun 10, 2017
186
Hamburg/NY
P.S. Until the new Cap comes in, have a pool party or such to keep the water circulating till then. Don't want this to set your TFP back :D
 
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