Troubleshooting pump that hums but moves no water

[CreedenceTapes]

My pump powers on but isn't moving any water. I can hear it humming when it gets power.

I first observed the problem when I turned off the pump to check the strainer basket. It was working fine before I cut the power, and the strainer basket had only a few tiny leaves in it, so I turned the pump back on. There was nothing but the hum.

I figured it was the start capacitor, so I ordered another. I checked the new capacitor before putting it in, and it was slightly above spec. I checked the old one after I removed it, and it was just barely under spec. I powered on the pump, but it did the same thing.

I can rotate the impeller with my fingers, and can't feel any debris in the area.

What else could it be?

 

[Mdragger88]

How old is the pump motor?
Can you post some pics along with the model & serial numbers while we wait for some others to come along?

 

[CreedenceTapes]

How old is the pump motor?
Can you post some pics along with the model & serial numbers while we wait for some others to come along?

I believe the motor was installed in April of 2021. It was here when I bought the house, but the owner was in the good habit of writing in-service dates on most of his purchases.



I'm happy to take specific pictures of the pump on request, but for now this one shows relevant information:

 

[JamesW]

The motor was made on the 94th day of 2020.

Can you show the pump model number?

 

[JamesW]

Can you show the wiring compartment?

Maybe a corroded centrifugal switch.

If the contacts are not making good contact, then the capacitor is not in the circuit during attempt to start.

Check the voltage at startup.

 

[JamesW]

Pump Centrifugal Switch - Further Reading

www.troublefreepool.com

 

[CreedenceTapes]

Thanks, guys!

I went out to snap some more photos. I took the retainer clip off the cap, and turned the cap over to get a pic of the terminals. Then I snapped a pic of the wiring and put the cap back and secured it with the retainer.

I powered it on to check the voltage (both legs a little over 120v) and it spun right up. Primed right away and is running as we speak. I powered it off and on via the timer switch a few times and it seems to be doing fine now.

What should I be on the lookout for now?

 

[JamesW]

Can you show the wiring compartment?

Can you show the pump model number?

 

[CreedenceTapes]

Can you show the wiring compartment?

Can you show the pump model number?

Give me a couple of minutes on the model, but here's the wiring:

 

[JamesW]

Maybe an issue with the centrifugal switch (Copper V) contacts.

You might be able to carefully clean the contacts with contact cleaner or maybe super fine sandpaper.

Be careful to keep the wires to the capacitor tucked behind the capacitor stand posts because if the wires get in the area where the centrifugal switch weights swing out, the wires can get snagged and ripped out.

The weights might be sticking in the open position.

 

[CreedenceTapes]

Can you show the wiring compartment?

Can you show the pump model number?

I'm not finding a model number. I'm betting this is because they replaced the housing as a result of the home inspector finding it to be leaking when we were buying the place. But here's what it looks like.

 

[JamesW]

When the pump is off, the weight is down and the V contacts are closed.

When the pump is on, the weights are up and the copper V contacts are open.

Your weights look like they might be up when the pump is off.

 

[CreedenceTapes]

Maybe an issue with the centrifugal switch (Copper V) contacts.

You might be able to carefully clean the contacts with contact cleaner or maybe super fine sandpaper.

Be careful to keep the wires to the capacitor tucked behind the capacitor stand posts because if the wires get in the area where the centrifugal switch weights swing out, the wires can get snagged and ripped out.

The weights might be sticking in the open position.

View attachment 551027

Sincerest thanks. The markups are especially helpful. I need to double check the placement of those wires.

 

[JamesW]

This weight swings up due to centrifugal force when the motor is on.

When the motor is off, the weight gets pulled back into the down position by the springs.

You can feel if the weight swings up and down smoothly.

Sometimes the weights get stuck open and this makes the contacts always open, which means that the capacitor is not in the loop for starting.

 

[CreedenceTapes]

When the pump is off, the weight is down and the V contacts are closed.

When the pump is on, the weights are up and the copper V contacts are open.

Your weights look like they might be up when the pump is off.

View attachment 551029

Yeah, I definitely need to check on that. From memory, I don't think I saw it in the right position when it was powered off. I'm probably going to let it run overnight and get back into it tomorrow. It was down at least 48 hours.

 

[CreedenceTapes]

I have two pumps, both essentially the same model, neither acting right. The most important is the main pump for my pool/cartridge filter, so I'll seek help with it first.

Somehow, after spending a few hours completely submerged in salt water during Hurricane Helena, my old Hayward Super II main pump fired right up the next day. Other than being a little noisier than it was before (possible bearing noise?) it ran fine.

Within a week or so, it failed to start after (one of the many times) I stopped it to clean the filter. It would buzz loudly, but it wouldn't seem to turn over. Because it behaved pretty much the same way the last time the start capacitor went bad, I ordered another start capacitor. I tried it again after a few hours, thinking maybe the capacitor could have built up some charge. Nada. Had I thought to do so, I would have turned off the mechanical timer at that time, but I didn't.

The next morning I awoke to the pump running, thanks to my not having remembered to turn off the timer. I let it run non-stop for a few days till a start capacitor arrived. This morning I power off the pump and put in the new capacitor. I had the same issue. The pump would buzz loudly but not restart after several attempts. The v-switch and the centrifugal weight seemed to be moving and operating as they should, and the crank shaft turned freely and easily by grasping the centrifugal weight and turning. I gave it power with the cover off, but couldn't see anything move. I definitely heard the buzzing when it had power.

I decided then to put the old capacitor back in, button it up, and seek some TFP wisdom. After it was all back together, I gave it some power just to see what would happen — of course it started right up and is running fine as I type.

There are pre-saltwater-inundation pictures of the pump in question in this thread. There was definitely some corrosion evident from the saltwater when I was in there today. Now that I think of it, there was some black goop in the rear cover as well. Maybe that's important and someone knows what it is.

 

[ajw22]

Sounds to me like your pump has had this intermittent behavior since January. It may have nothing to do with the storms and flooding.

Motors would occasionally get a dead spot on the armature and not start unless you spun the motor and moved it off the dead spot. I wonder if you have something like that internal with the motor.

 

[CreedenceTapes]

Sounds to me like your pump has had this intermittent behavior since January. It may have nothing to do with the storms and flooding.

Motors would occasionally get a dead spot on the armature and not start unless you spun the motor and moved it off the dead spot. I wonder if you have something like that internal with the motor.

I suppose that's possible, but it didn't miss a start from the time of the capacitor change in January till after being flooded a few weeks ago. That's being started at least once daily — frequently more, due to cleaning the strainer basket, filter, or some other reason. Also, before changing the capacitor out in January, I rotated the impeller to make sure that wasn't making it hang. It wouldn't turn over even after that. I've never torn one of these things down completely, but I'd guess that rotating the impeller should rotate the armature. (?)

 

[ajw22]

The new capacitor you got could have infant mortality. We have seen a lot of defective new parts since Covid.

 

[CreedenceTapes]

The new capacitor you got could have infant mortality. We have seen a lot of defective new parts since Covid.

Thanks, that crossed my mind also. I have another that I'll try. I think I should probably scrub the contact points on the V switch too.