Time for new pump?

[20fathoms]

Howdy all, new to the forum and need a bit of advice before the next freeze sets in.
Our 1 yr old pool pump recently went Tango Uniform...motor will kick on, hum for about 10 secs, then kick back off. As it tries to start, water does swirl in the strainer but only 10% of normal strength & speed, very weak. So far I have checked impeller and pipes for clogs (none found), motor shaft spins freely and quietly. It does not trip breakers, shows correct voltage on both sides of the breakers, the timer/on off switch, and at the motor itself. All contacts were clean. Replaced the capacitor with an identically rated replacement without change in condition. Does anyone have other trouble shooting ideas before I bite the bullet on a new motor?

Thanks in advance

 

[JasonLion]

Welcome to TFP!

I would check a few other things first. Start by verifying that the correct voltage is reaching the motor. It is possible for a short or loose connection to halve or double the voltage at the motor which could result in something like what you describe. Another possibility is a large air leak on the suction side, so the pump is drawing in lots of air and very little water. That seems unlikely as that normally turns up a vigorous froth in the pump strainer basket, but worth ruling out. Another possibility is a defective motor overheat switch. That is tricker to check, but see if the motor is getting really hot, if not the overheat switch might be triggering early.

 

[20fathoms]

Thank you very much for the quick reply. I confirmed correct voltage (within 10%) before/after the breakers, before/after the timer on/off switch, and at the motor terminals. Where is the overheat switch located and what does it look like? is it something that can be by-passed in an emergency?

Thanks again,