How To Replace a Pool Pump Capacitor

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Save yourself the cost of a new motor. Check the capacitor first. When you turn on your pump and the motor produces a humming sound, the motor may be frozen so that it won't turn or you may have a bad capacitor. Check the capacitor. It can be replaced for a fraction of the price of a new motor. Note: Some motors have two capacitors: a run capacitor and a start capacitor. If so, check both.

Click Here to View Pump Motor Parts (Including Run & Start Capacitors, Bearings, and Switches) 


Video

Step by Step

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Step 1

Turn off the power to the pool pump. For maximum safety turn the power off at the circuit breaker.

Step 2

Depending on the make of the pool pump, the capacitor will be under a hump cover on top of the motor, or it will be under a cover on the electrical end of the motor, or both. Some pumps have both a run capacitor and a start capacitor. The run capacitor will generally be rated at 15-50 MFD and 370 VAC. The start capacitor will generatlly be rated at 50-400 MFD and 125 or 250 VAC. This picture shows the location of the capacitor under a hump cover.

Click Here to View Pump Motor Parts (Including Run & Start Capacitors, Bearings, and Switches) 


Step 3

This picture shows the location of the pool pump capacitor at the end. In either case the covers are normally held on with two screws. Remove these screws to take off the cover and expose the capacitor. This capacitor is about the size of a roll of half dollars.

Step 4

Pool Pump Capacitors store an electrical charge that can shock you even when the power is off. Before removing the capacitor, discharge this energy by placing a screwdriver across the leads of the capacitor. CAUTION: Capacitors have been know to explode when shorted out. For your protection wear eye protection and place a cloth over the capacitor before shorting it out.

Step 5

If the capacitor is located at the end of the pool pump, remove the single screw that secures a clip holding the capacitor. Note how the plastic strip is positioned between the clip and the capacitor. It will have to be replaced in this position to keep the capacitor from shorting out on the motor. If the pool pump capacitor is on top of the motor, it should be free after you have removed the cover and the capacitor's leads.

Click Here to View Pump Motor Parts (Including Run & Start Capacitors, Bearings, and Switches) 


Step 6

Remove the leads to the pool pump capacitor. Note the placement of the leads so that you can restore them to their correct position when you reconnect them.

Step 7

Check the rating on the pool pump capacitor for replacement specifications. They will vary by manufacturer. Look for their MFD (or uf) and VAC specifications. For example, this one is a start capacitor rated at 124-149 MFD and 125 VAC. Try to replace the bad capacitor with an identical capacitor. If the exact capacitor is not available, you can use one with slightly higher capacitance. Do not use one with a lower rating.

Click Here to View Pump Motor Parts (Including Run & Start Capacitors, Bearings, and Switches) 


Step 8

Use a multimeter to verify that the capacitor is bad. Using the lowest ohms setting, touch the meter leads to the pool pump capacitor's terminals. If meter remains at 0, you know that the capacitor is bad. Check the new capacitor to verify it is good. First short out the terminals on the new capacitor to reset it. Then touch the meter leads to the capacitor terminals. If the capacitor is good, the meter will jump up to the other end than slower back off to 0.

Step 9

Connect the motor leads to the pool pump capacitor and secure the capacitor in place as required. Watch the placement of the plastic strip as mentioned above.

Step 10

Replace the cover.

Step 11

Reestablish power at the circuit breaker.

Comments

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(41 to 80 of 212)

 Posted: 1/28/2018 

Hello, First off, your site is amazing. I love that you genuinely want to sell people the correct product not an entire system. So, after reading comments I see that my pump when I turn power just quietly hums. Never starts up. Do you think that this is a start up capacitor issue? I have a century ust1102 1 hp motor on an in ground pool.
 Reply

 Posted: 1/2/2018 

Caleb, The current run capacitor for B2853 is 2523057-001, 30 MFD, 440 Volt, 2” diameter. Older versions used a 30 MFD, 370 volt capacitor (5270-05) which was 1 ¾” diameter. Kit 10003946-001-001, has the 30/440 cap, with a larger housing to accommodate the larger capacitor. If you have the older capacitor, you can still substitute the larger 440V capacitor (with the larger housing). It is more resistant to voltage spikes.
 Reply

 Posted: 12/31/2017 

Hello, I need a replacement run capacitor for a Century Centurion. Label states following info: Cat: B2853 Serial: 03413CH Part: 0-F56AA37A01-04 HP - 1 SF - 1.25 RPM - 3450 VOLTS - 230/115
 Reply

 Posted: 11/13/2017 

Bret - I'd try replacing the capacitor first. That's the least expensive fix.
 Reply

 Posted: 11/7/2017 

I have a top capacitor in the casing on top of the pump. Mine just blew off one day while it was running....casing and all was blown away from the pump. The capacitor was extremely hot, so assuming it overheated. Do you think I just need to replace the capacitor or do you think the motor may be damaged as well? Thanks
 Reply

InyoPools Product Specialist  Posted: 8/28/2017 

ebv128 - Check that the new capacitors have the same specs as the original capacitors. Then retrace your replacement steps to see if there was anything else you may have done to affect the switch. Check the switch.
 Reply

 Posted: 8/26/2017 

With the help of the video, I have replaced both the start and run capcitors on my Sundance Palermo 2005 2-speed emerson motor. However, now the first speed is not as strong as it used to be, and i need to push the button twice for the high speed to kick in and then off, and then on for the first speed to kick in. Sugggestions, please
 Reply

InyoPools Product Specialist  Posted: 8/14/2017 

Anónimo - I'd try replacing the capacitor(s) first. You may have two capacitors, a run, and a start capacitor. They are the easiest repair. I can't help you much without knowing what pump you have. Do a search on our website for your pump. Once you find the pump's product page, look for the link to it user's manual. There should be a trouble shooting section at the end of the manual.
 Reply

 Posted: 8/10/2017 

I have a pool pump that stopped working recently. There is a window on top of the motor where you can see how long it will run (2hr, 4hr, 6hr...24hr) and there is a timer button to select how long you want it to run and an on/off button. When the motor is plugged in, the light indicator for the hour selection blinks on and off, telling you that it is off. When you push the on/off button, it stops blinking (indicating that it is on) and the motor usually runs. The problem is that now, when it is plugged in, the light blinks and everything like normal, but when you turn it on, the light stops blinking but the motor doesn't run like it would usually do. There is no humming, no sound at all coming from the motor. The light indicator acts like it normally would, but the motor simply doesn't run or make a sound. Would the capacitor be the issue, or is it another problem. I can provide details if needed, please let me know and I hope to hear a response soon.
 Reply

InyoPools Product Specialist  Posted: 8/7/2017 

Ed - If the motor is humming, it's a good bet that one of the capacitors is shot. Try replacing the start capacitor first, behind the back cover, then replace the run capacitor. on top.
 Reply

 Posted: 8/6/2017 

I have a Hayward 2.5 super pump that quit while running, will not start and makes a humming noise. There is a capacitor on top is there also a capacitor behind the cover on this model. thanks
 Reply

InyoPools Product Specialist  Posted: 8/5/2017 

Terrell - I did not receive the picture through this comment page. Could you provide the motor's CAT and Part # along with it's HP, SF and amps?
 Reply

 Posted: 8/2/2017 

My capacitor went out, but my motor is only three years old. Here is a picture of the label: The Label reads:
Century Centurion
Switchless Motor
No Switch * No Governor
2514514-001

Can you tell me what kind this is and if so, do you carry it?

 Reply

 Posted: 7/18/2017 

I have swimming pool pump that is being used as a well pump. I was told the electrical start component has went out. I would like to send you a pic but there is no option. My starter capacitor does not look like the ones you are showing. Do I need to replace whole unit?
I was having to plug it in everytime I used it. Then one day when I plugged it in, it went proof at the junction box.

 Reply

InyoPools Product Specialist  Posted: 7/13/2017 

Anonymous (UST1152) - According to our motor rep: "The capacitor only sees one-half the circuit, so it can use the 110-125VAC capacitor".
 Reply

InyoPools Product Specialist  Posted: 7/13/2017 

Anonymous (UST1152) - Thank you for your feedback. You make a good point. I will verify this with our motor rep.
 Reply

Anonymous  Posted: 7/12/2017 

Hello,

In the following exchange your recommendation for a 110-125VAC Start Capacitor has me concerned... Since the UST1152 can be hooked up in a 230VAC configuration shouldn't the Cap be rated at least that high?

RJL Posted: 07/05/2017 18:55 PM Latest

We have an A.O Smith 1 1/2 HP motor for our in ground pool. On the top of the label it says "UST 1152" and along side the motor mod tab on the cover it lists it as "C48L2N134C1", Ser 10010CH. Anyway when I got home from work I noticed there was no water movement in the pool. It's scheduled to start up at 1000/am. No hum coming from the pump. This was at about 300/pm or so. I turned the switch off and on again it it hummed for a few seconds, 10 or so and turned off. How many capictors on this model? Does it sound like a capictor issue?

Thank you, JAM


Inyopools Posted: 07/09/2017 12:34 PM Latest Inyo Product Specialist

RJL - Replacing the start capacitor on your motor is a good place to start. The start capacitor for a UST1152 motor is Capacitor, MFD 161-193 (BC-161) 110-125VAC.

 Reply

InyoPools Product Specialist  Posted: 7/11/2017 

Slamfam - I'd check to make sure you have the right capacitor. Tha start capacitor you bought is for either a 1HP or 1 1/2HP uprated motor, like a UST 1102 or a UST 1152. Make sure your wire connections to the pump are tight. Make sure the motor shaft spins freely. Check that the governor is not stuck open. Other than that, you may have a short in the motor windings, which generally means a new motor.
 Reply

 Posted: 7/10/2017 

I just replaced the capacitor on a Hayward Super Pump (like the one in the video). When I turned on the power, it tripped the breaker. The new capacitor is rated the same, 161-193 MFD, 110-125 VAC. Is it possible the new capacitor is bad or am I looking at a new pump? The problem started Saturday the 9th. I turned off the pump to backwash the pool and when I turned it back on it did not start but was humming so I started with the capacitor. Any help would be greatly appreciated.
 Reply

InyoPools Product Specialist  Posted: 7/10/2017 

mcol75 - The capacitor for you motor, 7-187582-02, is Capacitor, Run 370v 35 Mfd (rd-35-370).
 Reply

 Posted: 7/9/2017 

Hi our capacitor is out for our 2.0 HP pump (AO Smith 7-187582-02). I cant read the size info on it anymore. What size capacitor should I order?
 Reply

InyoPools Product Specialist  Posted: 7/9/2017 

RJL - Replacing the start capacitor on your motor is a good place to start. The start capacitor for a UST1152 motor is Capacitor, MFD 161-193 (BC-161) 110-125VAC.
 Reply

 Posted: 7/5/2017 

We have an A.O Smith 1 1/2 HP motor for our in ground pool. On the top of the label it says "UST 1152" and along side the motor mod tab on the cover it lists it as "C48L2N134C1", Ser 10010CH. Anyway when I got home from work I noticed there was no water movement in the pool. It's scheduled to start up at 1000/am. No hum coming from the pump. This was at about 300/pm or so. I turned the switch off and on again it it hummed for a few seconds, 10 or so and turned off. How many capictors on this model? Does it sound like a capictor issue?

Thank you

 Reply

InyoPools Product Specialist  Posted: 6/26/2017 

Anonymous (3400vs) - Not sure if the 3400VS has a start capacitor, but if it does, replacing it would be a good place to start. The capacitor would be under the end electrical cap if it has one.
 Reply

Anonymous  Posted: 6/23/2017 

My hayward 3400vs motor won't start..could Ithis be the start capacitor?
 Reply

InyoPools Product Specialist  Posted: 6/20/2017 

Splashed - Most pool motors capacitors cost between $15 and $30. See Capacitors. So I'd recommend changing the capacitor(s) before buying a new motor. If your repairs are going to take a couple of days, you might throw in a couple bags of shock treatment especially if your pool is starting to turn a little green. Most pools only have 1 skimmer.
 Reply

 Posted: 6/19/2017 

So, our Hayward pump is humming, and from what I sm learning, if we want to replace the capaciter, that is a good sign. But heres what. From my research, they run about 150 estimated each and a brand new pump is 325. My experience with most engines or electrical parts is if you replace one, the other is usually not far behind. Our pump motor is an AO Smith and to replace with a Hayward, would be less expensive than buying two capaciters, and a lot less work. One of my concerns is what about why this happened? Is there a clog or problem? We have to find that. We cannot backwash to clean sand, ir flush a line, etc., so I guess this is a good time to replace sand. Should we load the pool with anything to keep anything from growing while we get tbe parts and fix this? Also we have only one skimmer... is that protocol for most pools? We are novices, we bought this house, this pool, these issues. Grrrrrr
 Reply

InyoPools Product Specialist  Posted: 6/13/2017 

Ugggh - Your O-173840-23 motor is an AO Smith Booster Pump Motor - B625. It has one start capacitor on the top of the motor, Capacitor 124-149 Mfd 125v (BC-124).
 Reply

 Posted: 6/12/2017 

I have a AO Smith Century Pool O-173840-23 pool pump for my bottom sucker. Hums then shuts off. It has a capacitor on the top. Does it have one in the housing too?
 Reply

InyoPools Product Specialist  Posted: 6/1/2017 

Brenda - Unfortunately, we do not carry this pump/motor and I can't locate in on the internet with the numbers you provided. If this motor has a capacitor, it would be under the electrical cap on the end of the motor. Look for burn marks. Replace the capacitor, is applicable. If no luck, your motor probably needs to be replaced.
 Reply

InyoPools Product Specialist  Posted: 5/30/2017 

JenRM - This motor, 7-184981-23, is an A.O. Smith Motor 56J Threaded, Up rated 1 Hp (b228se). It has no start capacitor, only a run capacitor - part #, 5270-05, 370V, 30 Mfd. Check the run capacitor for damage. They usually bulge out at the ends. If it looks good, your motor probably has a short in the windings and you may need a new motor.
 Reply

InyoPools Product Specialist  Posted: 5/29/2017 

Glo - This motor only has a run capacitor, no start capacitor. The run capacitor is mounted on top of the motor under the bump. I'd try replacing the run capacitor first but the humming might be due to a short in the windings which generally means a new motor.
 Reply

InyoPools Product Specialist  Posted: 5/29/2017 

Clint - If this motor has a start capacitor, it will be behind the electrical cover like in this guide.
 Reply

 Posted: 5/29/2017 

I have a waterway wet end above ground 2hp pool pump. It's humming, and kicks the breaker. It won't start up, and I've even tried jump starting it. I can turn the screw with a screw driver, but no luck starting it. Is it the run capacitor? Here is the info regarding model number, etc:
Model# SD-20-1N11CD
Part# PX1200-6

 Reply

 Posted: 5/29/2017 

Hi,I have a sp2607x10 Hayward pump with a 1Hp
motor, replaced 8 years ago, part 7-184981-23. The info I found in the motor manual says the capacitor is '2443' but I can't relate that back to something I can buy. I see 370vac and 6% and 307 on the capacitor (I don't want to remove it until I have the replacement). Can you help me with what capacitor I need to get for the replacement? The motor just hummed when I tried to start it this year and I can't feel any debris in the impeller so I'm hoping it's the capacitor.

 Reply

 Posted: 5/27/2017 

I have n A.O. smith part 7-165199-05. 1HPpool pump. I am trying to get into the capacitor but my screws are stripped. Does this model have a start and run capcitator? Only hums when I start it. Do I also need to get into the motor? Would that be the run capacitor on the inside and the start on the outside? Might need a manual and two capacitors. Please advise.
 Reply

 Posted: 5/26/2017 

I have a Ningbo Tuozhan 1 HP motor Model number RS4G24213L and hums when to turn on the power but I can get it started by using a screw driver to spin the motor shaft end. Can you tell me if this motor has a start capacitor and where is it located? I'd appreciate your help. Thank you very much.
 Reply

InyoPools Product Specialist  Posted: 5/19/2017 

David - Your pump motor uses a 25 MFD, 370 Volt run capacitor. It does not have a start capacitor.
 Reply

 Posted: 5/18/2017 

Ok, my turn..... I have a Sta-Rite Max E pump model # P6E6C-204L. Can you tell me how many capacitors it has and what the correct replacement(s) would be?

Thanks in advance.

 Reply

InyoPools Product Specialist  Posted: 4/21/2017 

Raymond - I would wire the capacitor as shown. It connects to three different circuits including a startup circuit. See Step 8 in our guide on "How the Common Capacitor Start Pool Motor Works".
 Reply