Pump stopped working only to work fine two days later.

[Cecil]

Why would a magnetic drive pump stop working (just hummed) only to have it run just fine a couple of days later?

I tapped on it to free any possible stuck impeller with no success. There was no blockage or gumming up anywhere as far as i could tell.

On a whim a couple of days later I plug it in and it works just fine! I have a new one coming so I guess now I'll have a back up for my back up! Just call me NASA!

[Crusty]

I have had this happen a few times with pumps, Cecil. I cycled the pump on clean water with chlorine (1part chlorine :2parts water at 10% sodium hyperchloride) for an hour to remove any organic build up. Flush with clean water and plug it back in again. I had this bypass built in so I can simply add a bucket to the side and turn the tap as a part of maintenance.

[kellenw]

I too wonder why this happens Cecil. I've had at least 5 or 6 mag pumps do this in the past several years.

[Cecil]

I'm sure it's like Crusty says: organic matter build up. My guess is the organic matter builds up a slimy sticky substance which causes something to stick? And having the pump dry out perhaps broke the seal that was causing something to stick?

I'd like to take the pump apart (at least partially) when I'm not using it to get a good assessment of the situation and make a WAG.

[arachdog]

The trouble with a magnetic drive as opposed to an induction drive (which is more common in larger pumps), is you can only have two poles. This means that there is certain rotor position where there is literally no torque being applied to the rotor. If the rotor stops in that position for whatever reason, it doesn't take much fouling at all to hold it there. But don't take my word for it, feel it for yourself. These kind of pumps are easy to dissemble, you just pull the plastic bits in the right direction. Plug it in, grab the rotor with your fingers and turn it till you find the dead spot.

[Cecil]

The trouble with a magnetic drive as opposed to an induction drive (which is more common in larger pumps), is you can only have two poles. This means that there is certain rotor position where there is literally no torque being applied to the rotor. If the rotor stops in that position for whatever reason, it doesn't take much fouling at all to hold it there. But don't take my word for it, feel it for yourself. These kind of pumps are easy to dissemble, you just pull the plastic bits in the right direction. Plug it in, grab the rotor with your fingers and turn it till you find the dead spot.

Thank Adog. Makes sense to me as this only happens if I turn the pump off and back on. I had the new one do it to me too. I unplugged and plugged it back in a few times and it started running again.