Pump hum and delayed start

[Jodester]

Well, since after it hums then stops, then starts up about 30 seconds later just fine all by itself, doesn't that mean that there is nothing impeding the impeller? It continues to run fine all day after that, even if I shut the pump off to clean the skimmers and then restart it. It only does the hum-stop thing in the morning when it's been off all night.

[Pappy]

Well, since after it hums then stops, then starts up about 30 seconds later just fine all by itself, doesn't that mean that there is nothing impeding the impeller?

Not necessarily. Many times things move more freely when warm than when cool. This happens because different materials expand at different rates. And I also recommend changing everything, if you go that route at all. If you have access to an ammeter, check the amp draw, both when the motor is humming and when running and compare that to published specs.

[Jodester]

I'm pretty certain at this point it's the capacitor. That would explain why the trouble only happens at morning start up. Throughout the day, while it's running, enough power has been stored so if I turn off the pump to backwash or something, it turns right back on. Kinda like a car battery on its last legs may have trouble starting in the morning, but once the car has run and charged it up, you can shut it off and restart it as long as not too much time has gone by for it to run down. I have a second (identical) pump for my spa, which I'm not using right now because I have a leak somewhere in the spa return line, so I think I'll try swapping out the capacitors and see what happens. If that does the trick, I'll just buy a new one and replace it. I may just bring it to a rebuild guy, though -- it's a little noisier than it usually is (there's a higher-pitched hum going on) that I think might be the windings.

[PoolDoc]

If you have access to a motor rebuild shop that will do the work cheaply, that would be a great option -- you'd get an almost new motor for -- hopefully -- considerably less than a new motor.

But in my area, the main rebuild shop is no longer a high production facility (most of the big manufacturers have shut down or left) and they now charge nearly as much to rebuild fractionals as the price of a new motor. From a Pro's point of view, that's a no-brainer: use the new motor with a manufacturer warranty: more profit and MUCH lower chance of an unpaid warranty call-back!