How To Determine Why a Motor Won't Start or Shuts Off

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This guide discusses the common problems related to a motor that won't start or once it does start shuts off after 5 minutes.

Step by Step

Top

Step 1

No power to the motor- Check for improper or loose connections, open switches or relays and blown circuit breakers or fuses. Check for broken power cords.

Step 2

Jammed motor - Check that the motor shaft rotates easily. If it's stuck, check that the impeller is not jammed with debris. Check that the impeller or diffuser is not broken. If the impeller is good, your problem may be bad motor bearings. Replace bearings/motor or impeller as required.

Click here to view motor bearings. 

Click here to view pump impellers.  

 

Step 3

Motor hums but will not turn over - Check for a bad capacitor. You may have two: a run capacitor and a start capacitor. Some motors have a governor at the electrical end of the shaft. Check that it is not stuck open. If your capacitor(s) and governor are good and the motor shaft rotates easily you probably have a burned out motor coil and you will need to repair or replace the motor.

Click here to view motor parts.  

 

Step 4

Motor gets hot and shuts down - Generally due to low voltage or being overloaded. Check that the motor is wired correctly. If the motor is configured for 230V and has 115V coming in, it will shut down after running 3-5 minutes. Check for loose connections. Check for undersized wiring. For a hook-up to the circuit box of under 50', pumps of up to 2HP wired for 230V need No. 14 size wire, For pumps wired for 115V, the wire size must be No. 14 for 1/2 and 3/4 HP; No 12 for 1 HP; and No. 10 for 1 1/2 and 2 HP. Check that the motor is not overloaded. Does the pump have the correct impeller and diffuser for this motor? Is the impeller worn and rubbing on the diffuser. 

 

Step 5

Note: Most pump motors have Automatic Thermal Overload Protection. The motor will automatically shut off before the motor generates enough heat to damage itself. Once a normal heat level is reached, the motor will automatically restart. CAUTION: If the motor operates in this on/off mode for any length of time it will burn out.

Click here to view replacement motors. 

Comments

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(1 to 40 of 206)

 Posted: 6/2/2021 

I have a Hayward pump and it initially ran for about 20 minutes then I turned it off to finish cleaning the bottom of the pool. When I went to restart it now it makes a light couple of clicking sounds almost like a gas engine that wont turn over. I replaced the leaky o ring and checked all the breakers but I'm at a loss on what the issue may be
 Reply

InyoPools Product Specialist  Posted: 6/4/2021 

I suggest testing the pump's start capacitor and the line voltage to see if those are the things preventing start up.
 Reply

 Posted: 5/22/2021 

I just walked outside and my pool motor has stopped. The electric switch is in the on position and it won't go down to the off position. The breaker box switch was still in the on position as well. It was working fine last night
 Reply

InyoPools Product Specialist  Posted: 6/4/2021 

Have you checked to see if the motor is jammed? Have you tried resetting the breaker anyway? Have you done any troubleshooting other than checking the breaker?
 Reply

 Posted: 5/15/2021 

I installed my pump, I have power to the pump ((tested 240) but pump will not turn on. No sound at all. Checked old pump and same thing. What could be wrong if units are getting power?
 Reply

InyoPools Product Specialist  Posted: 5/21/2021 

You could have a bad breaker, loose connection. It could be a host of things. Do you have a multimeter that will help you test the voltages? 
 Reply

 Posted: 1/5/2021 

My pool pump makes a humming noise but won't turn on. Replaced capacitator, however, it keeps doing the same thing. What else could it be?
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InyoPools Product Specialist  Posted: 1/6/2021 

If the motor still hums after replacing the capacitor, the phase windings are most likely bad. If that is the case, we usually suggest replacing the motor. You can see more on how to test the windings here: How To Use a Multimeter to Test a Pool Pump Motor - Winding Resistance
 Reply

 Posted: 8/25/2020 

I replaced a LAo1N Booster pump for our cleaner with a brand new one eight weeks ago. It was working perfectly until a week ago. Tropical Storm Isaias created havoc in the Northeast and our house ran on generator power for the better part of 6 days while they repaired the power lines. Our pool equipment all runs on the generator as well. It was somewhere during the storm/post storm that the booster pump stopped working. The filter pump is working great. I checked all the wiring on the pump and on the control board and all looks in good. Lights on control panel light you push the cleaner button. The pump does not hum, get hot, nothing. Just dead. Any ideas? I am wondering if there was a power surge or something that damaged it but not the Filter pump. Thank you
 Reply

 Posted: 3/2/2021 

Have you had any luck fixing your pump? I have the exact same problem as you we froze up bad here in Texas a couple of weeks ago and now my pump won't turn on at all but I am getting power to it and the capacitor is good and the impeller spins easily
 Reply

InyoPools Product Specialist  Posted: 8/27/2020 

There could have been a power surge that knocked out your motor, but I would not rule out water damage. Try checking the capacitor: How to Test a Pool Pump Capacitor, and try spinning the motor shaft by hand to see if it has frozen up.
 Reply

Anonymous  Posted: 8/8/2020 

It rained a lot last night my panel was open I believe it got wet inside the pump turn on but then it turned off now it won’t start
 Reply

InyoPools Product Specialist  Posted: 8/20/2020 

The only thing you can do is give it time to dry out (a day or two) and hope that is all that needs. If not, you may need a new controller or motor.
 Reply

 Posted: 7/20/2020 

My pentair 342001 vs superflo will not start. if i hit a few buttons all the small green led lights will flash twice. Sometimes once. There is no error code, I have tried the breaker. Help?
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InyoPools Product Specialist  Posted: 9/9/2020 

It sounds like you have a bad control. Your best option is to contact Pentair to see if they can troubleshoot the panel. But usually, when they start acting up, you need to replace the control box or the whole motor assembly. How old is the pump? Is it still under warranty?
 Reply

 Posted: 7/16/2020 

My pool pump won’t turn on at all. There is no humming sound. The box is getting power but motor is not working. It is a Century switchless pump. Aqualink RS6 control panel shows the filter pump is lit up but nothing happening. Thoughts?
 Reply

InyoPools Product Specialist  Posted: 11/10/2020 

If you disconnect power from the motor, disassemble the pump, can you turn the motor's shaft by hand? Or, is the shaft locked in place, sometimes called "frozen"? If the motor shaft is frozen, your bearings have locked up; you would need to either replace the bearings or the whole motor.
 Reply

 Posted: 5/31/2020 

I've had this pump for less than a year n I plugged it in this year n no power to the pump !! What am I missing?
 Reply

InyoPools Product Specialist  Posted: 10/23/2020 

This guide tells you what to do in this case. Did you take the time to read and complete the steps?
 Reply

 Posted: 1/13/2020 

I just replaced my pump and and noticed that it will not turn off at the control panel even though it reads "off" on the display panel. It will only come on and go off by using the breaker. Any ideas on what caused this?
 Reply

InyoPools Product Specialist  Posted: 1/13/2020 

For some clarification, is this a single, dual or variable speed motor? When you say control panel are you rferring a mounted control on the motor, or a wall-mounted panel?
 Reply

 Posted: 12/7/2019 

We’ve owned this home 20 years. The motor was never replaced/worked on. It always ran great. Recently, it began humming & shuts off after 7 seconds (but the motor is pumping water). My son (Masters degree in electrical engineering) tested the capacitor and says it’s fine. I can easily rotate the impeller with my fingers. I also cleaned out the DE in the filter, but haven’t replaced it yet. Suggestions?
 Reply

InyoPools Product Specialist  Posted: 12/9/2019 

Did either you or your son test the line voltage or the phase windings?
 Reply

 Posted: 9/10/2019 

My motor runs just fine, however after it's been running for a few hours if I turn it off to empty the basket when I turn it back on it hums. What could cause that?
 Reply

InyoPools Product Specialist  Posted: 9/12/2019 

Humming is a sign of a failing capacitor.
 Reply

 Posted: 6/13/2019 

My pool pump won’t turn on at all. There is no humming sound. The box is getting power but it seems that the timer motor is not working. Could that be the problem?
 Reply

InyoPools Product Specialist  Posted: 6/13/2019 

What is the catalog or part number from your motor's label?
 Reply

 Posted: 5/30/2019 

Well....replaced the top cap (think is the run cap?)....and nothing....like dead....think it could be the start cap?? Thanks for any help
 Reply

InyoPools Product Specialist  Posted: 5/30/2019 

It could be a start capacitor issue. Take a look at this guide for troubleshooting: How to Test a Pool Pump Capacitor
 Reply

Anonymous  Posted: 5/17/2019 

When I turn it on My Polaris motor will hum for about 10 seconds or so then it will shut off. What could be causing this?
 Reply

InyoPools Product Specialist  Posted: 5/20/2019 

It could be a bad capacitor or one of the things mentioned in this troubleshooting guide. What troubleshooting steps have you completed so far?
 Reply

 Posted: 5/9/2019 

My pump shuts off randomly, usually every 10-15min, then turns back on after about 30sec. It's been an ongoing issue over the past few years, last year it didn't happen at all from what I remember, but in years before it has happened with varying frequency. The pump has been replaced within those years, but it didn't seem to make a difference. It doesn't seem to be related to heat, pump doesn't seem overly hot, or weather (hot summer days or cool spring/fall days). I'm have a easytouch system (about 10 years old) and century 1 1/2hp motor (2-3 years old). Any ideas why this is happening?
 Reply

InyoPools Product Specialist  Posted: 5/9/2019 

Hello Kelvin - My first thought was that the windings in the motor are going bad and that is causing it to randomly shut down. If the windings are bad, the motor should be replaced. Another possibility is that the relay that controls the pump is going bad. That or the wires at the relay are loose.
 Reply

 Posted: 6/1/2019 

I replaced the relay and so far it seems to have fixed the problem. Thank you for your help!
 Reply

 Posted: 4/29/2019 

I replaced my start capacitor. Turned to power on, it popped and tripped the breaker Now it doesn't come on at all Now what?
 Reply

InyoPools Product Specialist  Posted: 4/29/2019 

I would confirm the capacitor was hooked up correctly, then test it to determine if it is still good. 
 Reply

 Posted: 4/7/2019 

My pool motor runs during a quick bench test. But there is no re-action when it is installed on the pump. I measured 220v at the input. I have a Sta Rite Pentair pump and USQ 1152 motor. My next guess is the bearings but I can't understand why there is no noise and no movement at all when it is installed on the pump.
 Reply

InyoPools Product Specialist  Posted: 4/8/2019 

Joe - have you checked that the impeller and the diffuser are not blocked or locked up? Is there scoring on the impeller, diffuser, or seal plate which might be a sign of rubbing?
 Reply

 Posted: 4/8/2019 

There is 220 VAC at the input. But still nothing, no noise , no struggling, no hum, There is one thing different when testing on the bench. I didn't want to play with 220v so I switched the control knob to 115v just for the bench test. Then I turned it back to 220v. But I get no reaction when the motor is installed on the pump.
 Reply

InyoPools Product Specialist  Posted: 4/9/2019 

Have you tried applying switching the motor to 115 and applying 115-volts to the motor when it is installed on the pump?
 Reply