Pump Motor Locking Up Each Night - starts w/ manual crank

[Mtones9]

Lately the motor has been failing to properly start in the morning. I get the 5-10 second humming sound and then it cuts off. I tried a new capacitor and it didn't solve the problem however I am able to get the motor running by taking off the back cover and manually turning the shaft with wrench. After turning the shaft I can go flip the switch and it'll start running for the day. What's odd is that some mornings it'll start up on its own without the manual crank but over the last 2 weeks its been 50/50 on whether it'll auto-start each morning. I don't think there's any debris blocking the impeller because it'll run for the full day but it's odd that it'll completely seize up in the evenings to the extent that I can't manually rotate the impeller by reaching inside the

Any thoughts on other potential issues? Centrifugal switch? It's a rather old pump as evidenced by the pictures below and I just recently noticed the peeling paint & corrosion at the connection between the motor and the pump. I'm worried that a leaking seal there could've caused the problem...

 

[1poolman1]

You definitely had/have a leaking shaft seal. Surprised you're not mentioning any noise from the motor. Looking at the rust coming from the vent you may want to start thinking about a new motor.
You may have a bad spot in the windings in the motor. When that much water gets into a pump it can cause damage to the lacquer that insulates the wiring and allow a short or burn. If the motor stops with the rotor in that position, it won't start the next time power is applied.
Make sure your pump basket is intact. If is possible some debris is getting stuck between the impeller and diffuser, but I have never seen that problem on a WhisperFlo.

 

[Mtones9]

Thanks! the pump basket is definitely in good shape and cleaned out regularly so perhaps there is a short or burn.

Right before this started there were a few days where pools toys were stuck in the skimmer all day/night. Could that have caused excess water through motor and damage. Regardless I'll look for a new motor. Is it best to just look for an exact replacement or is there an upgrade/more modern alternative that I should consider?

Looks like this would be a direct replacement - Pentair Replacement Motor

 

[1poolman1]

Century ECM16SQU is a direct replacement VS motor for that pump. It will work with your existing timeclock. In the long run it is the best deal going.

The motor you referenced is a full-rated 1.5hp single-speed motor, that, despite the "energy efficient" description, is only about 3-5% more efficient than a standard single-speed motor (I did the math 30 years ago). It is a 2.25 total horsepower motor and actually illegal in this country since 7/2021 (DOE regulations). They are allowed to sell old stock. Your existing motor is an uprated 1.5 hp. motor with a total horsepower of 1.65. The V-Green motor is a 1.65hp motor, perfect match.

 

[Mtones9]

Thanks so much for the help. Should I have any concern that a VS motor would damage my Pentair FNS Plus filter? Its relatively new but I've heard that sometimes VS motors require higher end filters.

 

[1Sammy]

From your description of the impeller not being able to be turned by your fingers but can with a wrench says a tight bearing. Cheap fix if you can do yourself.

 

[proavia]

It looks like there is a small wet spot under the motor. Chances are the front bearing is starting to go bad due to water intrusion from a compromised seal.

How old is the motor?

 

[1poolman1]

Thanks so much for the help. Should I have any concern that a VS motor would damage my Pentair FNS Plus filter? Its relatively new but I've heard that sometimes VS motors require higher end filters.

Not sure where that information would come from. Your existing pump is a 1.65thp pump that runs one speed, essentially high, at all times. If you install the V-Green 1.65 motor and have it run at its highest speed only, your pump has not changed, it would still be a single-speed 1.65thp pump. The advantage is that you can, and should, run it for a long time at a lower speed to get the most out of a VSP, which is what your pump would become. It saves energy, allows for more chemical circulation (and production with a SWG), gives you long filter runs, and when the filter is in need of cleaning it cleans easier.

If you think of your filter system as the vacuum cleaner everyone has in their home, the filter is just the dirt collector/holder/bag. The pump "couldn't care less" what is catching the dirt, it just moves water.

 

[Mtones9]

It looks like there is a small wet spot under the motor. Chances are the front bearing is starting to go bad due to water intrusion from a compromised seal.

How old is the motor?

I don't know the exact age (we moved in 4.5 years ago and it was already here) but I think it's fairly dated. Do you think it's a seal plate issue or just the small seal that sits in between everything? I can try to replace either but would need to refer to some instructions.

 

[1poolman1]

I don't know the exact age (we moved in 4.5 years ago and it was already here) but I think it's fairly dated. Do you think it's a seal plate issue or just the small seal that sits in between everything? I can try to replace either but would need to refer to some instructions.

Many youtube videos on replacing the seal in a Whisperflo. Bearing are probably still bad. May still have a bad spot in the windings. You could take the motor to a motor shop that could replace the bearings, but rewinding the motor would be a waste of money because you could buy a new motor for less than that would cost.

 

[proavia]

Chances are the bearing is in need of replacement also. A new seal kit (Go-kit) will also be needed.
It may be beneficial to replace the motor with the one mentioned above - or a new VS pump.

Fill out your signature with pool, pool equipmemt (including manufacturers and model numbers) and test kit info.
This will assist us in providing help without having to ask for this info each time.

 

[Mtones9]

From your description of the impeller not being able to be turned by your fingers but can with a wrench says a tight bearing. Cheap fix if you can do yourself.

That would be great if that was the issue. Any tips on how to check? This is my first pool and first pool motor issue. Fairly handy if I can refer to basic instructions...

 

[Mtones9]

Sounds like a new motor is the best bet.

 

[Mtones9]

From your description of the impeller not being able to be turned by your fingers but can with a wrench says a tight bearing. Cheap fix if you can do yourself.

is there an easy way to check this?

 

[1poolman1]

is there an easy way to check this?

The only way to be sure the bearings have corroded to the point they won't let the motor turn is to open the pump and try to turn the impeller by hand. You will feel the bad bearing (99.9% of the time the one that is on the front of the motor). They mat even make a "grinding noise." Again, a multitude of YouTube videos on how to replace bearings. The fact hat you can get the motor to run by "manually" spinning it indicates the problem is probably somewhere other than the bearings being too "tight." There is no adjustment on a sealed bearing in a pool motor.

Or, trust that seeing all the damage that is visible to the motor will indicate that a). the bearing has been damaged and b). the windings have likely suffered some damage as well due to water intrusion.

If is an unfortunate fact of pool ownership that sooner or later, the motor will die.

 

[Michi swims]

is there an easy way to check this?

Hi… I am having the exact same problem with my pump. Have you been able to identify the cause of our mutual problem? And if so, how did you go about fixing it? I don’t want to have to keep manually turning the shaft/impeller by hand every time I want to turn on the filter. Any information is appreciated!

 

[Poolbreh]

A very common problem with whisperflo, the motors vibration will eventually cause the motor to pull away from the wet end. The bolts will eat into the motor itself, making the motor/impeller/diffuser no longer flush. It causes rubbing between impeller and diffuser and sometimes pulls or cracks the bolts at the seal plate. Taking it apart is the only way to see, if you see rubbing on one side of the diffuser you’ll know, any other parts will be noticeable to replace.

 

[Michi swims]

Thanks so much! I was trying to avoid having to open it up, but sounds like that's my next step. I appreciate you replying so quickly.