Pentair whisperflo wf-23 not pumping.

[Chris-ber]

I have an in ground pool with a pentair whisperflo wf-23, 3/4 hp pump.

Right now the pump runs, shaft spins, water churns, but it won't move the water.

I pulled it apart to check the impeller, it looks fine. The shaft spins freely by hand and it also spins when the pump turns on. After pulling it apart and looking at the impeller I filled up the filter, filled the pump to prime it like I always do, it draws very little water through the suction lines, doesn't full up the basket, and the overheat switch kicks the pump off.

I don't believe it's a prime issue or a leak issue. The impeller looks fine. I'm wondering about the run capacitor. Can it be "weak" and not allow the shaft to spin fast enough, or do you think I'm looking at another issue?

Thank you.

 

[bigredmachine81]

Obstruction in line possibly, clogged impeller, those two things will make the pump not fill up basket area with water.

Why do you fill the filter? you should not have to fill the pump every time to get it to prime, unless you cleaned the pump basket and it took out a lot of the water out when you removed it, if the pump does not prime on it's own every time, and you have to always add water to it, then there may be a problem, without knowing exactly why you have to fill the pump to prime it as you said, i can't say until you explain more.

Right now it is not picking up prime, if it were you would notice the gradual flooding of water in the basket area that gets stronger and stronger until the pump is running full blast, "prime" is the initial start of the motor after being off, that gradually builds the pump up to running speed, it is not priming the way it is now, prime should be instant when the pump is turned on, or maybe 30 sec- 1 min. in a system that has a good tight seal

What voltage is the motor, it almost sounds like electrical possibly to, does the motor seem slow to start when turned on? or does it buzz or hum loudly at first? does it sound like it runs half speed compared to how it used to? how long does it take to thermally overload and shut down? does it smell burned around the motor at all?

You stated you don't think it's a prime, or leak issue, like i explained above it is definitely a prime issue, "it is not picking up prime"

As far as a leak issue you can't just say you don't think it isn't that, you have to be able to know.

It's hard to go off of the limited info you provided.

How old is the pump? is it possible the lines could be clogged? etc, etc.

 

[Jimrahbe]

Chris,

The number one reason that a pump will not prime is an air leak under the pump basket lid. Take out the O-Ring and inspect it. If ok, lube it will silicon grease and try it again.

Jim R.

 

[Chris-ber]

It's a 230v.

When the pump kicked on yesterday it wouldn't pump, water in the basket just churned but wouldn't get going. The thermal switch/relay in the pump kicked on and shut the pump off. Cooled down a little then I could turn it on again to the same results. So that's when I drained it, took it apart and looked at the impeller. Put it all back together and cleaned everything. It all visually looked fine. That's the reason I filled the filter and pump up, because I drained it. I let it sit all night, letting it completely cool off. Turned it on this morning and it looks like it was priming and filling the basket like it always had in the past. Then the thermal switch kicked the pump off again. It almost seemed like it shut the pump down too quickly, as it usually takes a few minutes to completely fill the basket and go full on. But now it's kicking off rather quickly.

I also noticed a strange physical humming, higher pitched than normal but not a full bearing squeal. So now I'm wondering if it isn't a bearing issue maybe causing it to over heat quickly. Like I said everything spins easily by hand, but it's a possibility. I don't know the age of the pump, but the house is 10 years old. Pump may be that old, could be as new as 5 years old...That's when we bought the house.

I do smell DC motor heat when it shuts off, so I know it's getting hot. Normally it takes a few minutes to get full prime anyway, but it never over heated in the past. Now it's shutting down quicker and not getting full prime. It gets to the point where the basket is almost full, and still shuts down. Seems to be working at full speed. No leaks outside the pump or on any of the piping, fittings, or filter.

 

[Chris-ber]

Ok, starting to think bad bearings or motor issue. Ran it again a few minutes ago and it seems to be moving water, almost filled the basket within a few seconds of turning on, but turned off a few seconds later. The overheat switch is kicking in, I hear the click and it shuts off. A few minutes later it clicks again and the pump starts. I tested power to and at the pump, reading 240v. I did a cap test on the run capacitor and it reads correctly. I'm thinking something is causing it to over heat quickly, which leads me to bearings or motor itself.

 

[mas985]

I'm thinking something is causing it to over heat quickly, which leads me to bearings or motor itself.

That is the most likely scenario. Although an obstruction near the impeller could also cause the same issue but since you had it apart, I am assuming you did not find anything.

 

[Chris-ber]

That is the most likely scenario. Although an obstruction near the impeller could also cause the same issue but since you had it apart, I am assuming you did not find anything.

No, I didn't find anything that would appear obvious. The impeller and diffuser were clear and clean. I went ahead and removed the motor to get a better look inside, once everything was apart I did hear a slight grinding when I turn the impeller. It spins freely, but isn't as quiet as I think it should be. I'm an automotive guy and have seen my share of bad pulley bearings, spin in hand but when spinning at over 1k rpms, it really starts to squeal and heat up. The motor itself is pretty rusted underneath. So I'm leaning towards just replacing the motor. It's under $200, plus $20 for new seals. Might as well bite the bullet and replace bullet.