Pentair Whisperflow pump (2.5 years old)

geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
I came out to the pool last week and the noticed the pump wasn't running just sitting there humming. Did some research and replaced the capacitor and fired it up and it worked fine for a week.

Came out to the pool yesterday and found the pump fuse at the panel blown. Reset the breaker and turned on the pump and it made a pop sound and blew the breaker again. I thought I saw a very small puff of smoke come out of the back of the motor. Thought the capacitor blew but checked it and it still looked brand new.

At this point I figured that the pump was toast but I decided to try and fire it up again. This time it came on but sounded much louder than normal and it appears to be sucking some air along with moving some water. Pressure at the filter was at like 1 (normally is at 10). Pressure at the pool returns was also low. Basically, it looks like the pump isn't priming itself as normal. My pump is lower than the pool so I have never had any issues with the pool pump priming itself.

As a test, I dismounted the motor so I could see the impeller and it spins freely and appears intact. I even fired up the motor (just for a second) while it was disconnected and it seems to sound fine.

I tried using soap suds to try to find an intake leak but found nothing obvious. I tried running a stream of water where a possible air leak could be to see if that would prime the pump with no success as well.

The pool guy came out this weekend and thinks it's a bad pump and is going to warranty it but from what I see (I'm an amateur) the pump appears ok. Obviously, I'm going to let him do what he thinks is going to fix it but I wanted to see what the forum thinks.

Has anyone had a pump situation where it was going bad and causing priming issues?
 

Poolbreh

In The Industry
Jul 31, 2021
272
San Diego
From my understanding if the uf rating is the same it’s fine. There was no signs of rubbing on the impeller and diffuser? For example the diffuser copper ring would be worn down more on one side and the impellar lip that fits into the diffuser would be worn more on side. It sounds like the bearings to me, and when it actually has water running through it, it will create more drag. Might be the reason you don’t hear it when everything is apart. The pump is primed, it just looks like it’s struggling to push water or air completely through, which brings me back to the bearings.
 

Mike1162

Silver Supporter
Jun 13, 2015
1,103
N Tonawanda, NY
You could try another capacitor. Sometimes new parts are faulty.
Make sure the motor shaft spins freely.
Check the impeller for debris.
Take the cover off the end of the motor & post a picture, . Any burnt wires or burnt wire smell?
 
Last edited:

ferretbone

In The Industry
May 24, 2016
161
tx
It sounds like a wire from the back of the motor is loose and could be arking with the pump body. From your video you have some kind of impeller issue or some thing else as well.
When a pump is turned off and on rapidly it can spin the impeller forward. I'm thinking a loose hot wire on back and now an impeller issue

Stop the pump. Open the pump lid and run the pump with the lid off. If the pump can keep up the with the water pushing from the pools suction side but not get rid of the water through the return its a return issue. From the impeller back.

A large air pocket or lock in the line
Again the impeller is maybe spinning free or loose on the shaft. Let us know
 

geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
I took a pic of the back with the cover off. To me it appears normal other than two old bees nests.

I didn't have a chance to do the test with the lid off but I did notice something a little strange. When I turned on the pump (to test the capacitor I orderd with the exact specs), as you all suspected it made no difference BUT I did hear water coming back down the return when I turned the pump off. Seems very strange and it has me totally baffled.endcap.jpg
 

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Mike1162

Silver Supporter
Jun 13, 2015
1,103
N Tonawanda, NY
You could confirm 230 volts between the two red wires. Power will have to be on & you need to be careful. Ask questions if needed.
I suppose you could also check the resistance of the windings. I never done this but think it's a valid test.
Power off.
Remove red wires
Check resistance between green screw & L1 then green screw & L2. Readings should be close.
 

JamesW

TFP Expert
Mar 2, 2011
28,212
Check the voltage and current while the pump is on.

Then, turn off the breaker and remove the red wires.

Remove the capacitor and then check the resistance from L1 to L2.

If the capacitor is charged, the windings are bad.

Can you open the pump and show the impeller from 2 different angles?
 
Last edited:

ferretbone

In The Industry
May 24, 2016
161
tx
I took a pic of the back with the cover off. To me it appears normal other than two old bees nests.

I didn't have a chance to do the test with the lid off but I did notice something a little strange. When I turned on the pump (to test the capacitor I orderd with the exact specs), as you all suspected it made no difference BUT I did hear water coming back down the return when I turned the pump off. Seems very strange and it has me totally baffled.View attachment 367107
Well that burnt paper wasps nest on the right of your picture is what caused your ark that I was looking for. That is what made the pop sound you heard, and kicked your breaker. The air vent in the back of the motor prolly blew the nest around and brushed it over the L1 and L2 screws causing the arks. Your motor/ cap are likely fine.

Now check the impellar, if its ok then the only thing left here is why would the water from the pump be so hard to push through the filter like it is in your video? A clogged dirty filter, a closed return line.

Edit
"BUT I did hear water coming back down the return when I turned the pump off. Seems very strange and it has me totally baffled"
That is because of the filter back pressure. Again see above. Impellar filter or return line closed. P.S you prolly have some dead cooked wasp inside your motor.
 
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geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
Haven't taken it apart again to check the impeller. The first time I didn't take off the diffuser off to really see the whole impellor. I'll do that when i get some time.

I'll let the pros check the voltage stuff when they come tomorrow....I think.

I checked the valve on my return line and it is surely opened. I turned it off just as a quick test and saw the filter pressure rise but no water was being returned to the pool. I know it's opened for sure.
 

geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
Well that burnt paper wasps nest on the right of your picture is what caused your ark that I was looking for. That is what made the pop sound you heard, and kicked your breaker. The air vent in the back of the motor prolly blew the nest around and brushed it over the L1 and L2 screws causing the arks. Your motor/ cap are likely fine.

Now check the impellar, if its ok then the only thing left here is why would the water from the pump be so hard to push through the filter like it is in your video? A clogged dirty filter, a closed return line.

Edit
"BUT I did hear water coming back down the return when I turned the pump off. Seems very strange and it has me totally baffled"
That is because of the filter back pressure. Again see above. Impellar filter or return line closed. P.S you prolly have some dead cooked wasp inside your motor.
I did clean out my FNS filter by opening up the tank and spraying down with a hose. Reassmbled and still same symptoms. Have to break down pump again to check impellor. Hope to get to that soon.
 

geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
Ok pictures of impellor attached. Looks fine to me but I've never seen what a bad one looks like. No play or slippage either. My ground wire was loose so I tightened it but still not fixed.

I also put my the valve into waste to bypass the filter and the problem is still there. I'd think that this would eliminate any issues with blockage from the filter all the way to the pool.

So lost on this one.....impellor1.jpgimpellor2.jpg
 

geewiss

Bronze Supporter
Jul 23, 2020
47
Centreville Maryland
Pool company came out yesterday and installed a new motor. This has fixed the issue and I'm good to go. Unfortunately they didn't let me keep the old one. I would of loved to take it apart to see what was wrong!!
 
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