How To Replace A Pool Pump Impeller

Written by:  Danny Rhodehamel
rate: 
 
 (3.1 OUT OF 5 STARS ON 25 RATINGS)

The location of the pool pump impeller is shown in this cut-away of a pump. The spinning action of the impeller when driven by the pump motor generates the water pressure in your pool system. Sometimes debris will get into the pump and will crack the impeller. In other cases the threads that hold the impeller to the motor shaft become worn causing the impeller to wobble and rub against the diffuser. This guide explains how to replace a bad pool pump impeller.

Tips & Warnings

Video

Things You'll Need

Step by Step

Step 1

For a quick introduction, this picture shows the operation of the impeller. Water enters the center of the impeller. As the impeller is spun by the motor, a series of blades, like a fan, pushes the water to the outside edges of the impeller where it exits through slots to be collected by the diffuser. For an expanded explanation of how a pump operates click How A Pool Pump Works.

Step 2

The first step in preparing to remove your pump's impeller is to turn off all power to the motor. For maximum safety turn off the power at the circuit breaker to the motor - usually located next to the timer box.

Step 3

Next you will have to relieve the pressure that builds up in the pump during operation. To relieve pressure turn the relief valve on top of the filter counter clockwise. Water will spray out initally as you see the pressure on the pressure gauge go to 0 psi.

Step 4

To extract the motor pump assembly from the pump housing, first remove the four 9/16" bolts that bind the motor pump assembly to the housing. Keep track of the washers. Note: Some Hayward pumps have six bolts.

Step 5

Pull the assembly apart from the housing.

Step 6

After the assembly is out, you should see the diffuser and diffuser gasket on the end of the assembly. If you do not see the diffuser or its gasket, check inside the housing.

Step 7

If the diffuser came out with the assembly, pull the diffuser off the assembly. It should snap off easily and expose the impeller.

Step 8

To remove the impeller you will twist the impeller off in a counter clockwise motion. However, the impeller cannot be freed from the motor shaft without first securing the motor shaft.

Step 9

Move to the other end of the motor shaft in the back of the motor assembly. Take off the two screws that hold the back cover onto the assembly.

Step 10

You will see the motor wiring and capacitor. To gain access to the end of the motor shaft you will have to remove the capacitor. Capacitors store power. To avoid a possible shock, lay a screwdriver across the two leads to short out the capacitor.

Step 11

Unscrew the single screw that hold the capacitor in place and push it out of the way. No need to disconnect the capacitor from its leads.

Step 12

Place a 7/16" wrench on the flat end of the motor shaft to secure the shaft from rotating. Note: Securing the motor shaft on other non-Hayward type pumps varies. Some pumps provide a slot on the end of the shaft to secure with a screwdriver. This slot is often accessable by simply taking off the end cap of the motor.

Step 13

At the impeller end, twist off the impeller counter clockwise. You may have to use a strap wrench to gently free up the impeller.

Step 14

With the impeller off you will see the motor shaft seal. One half on the impeller and the other half in the seal plate on the shaft. If you have not replaced the motor shaft seal and the pump is several years old, this may be a good time to replace this seal. For instructions on replacing this seal click How To Replace a Motor Shaft Seal. If you decide not to replace this seal, continue on to the next step.

Step 15

Grab the seal on the impeller and twist it off. Make a note of how the seal is positioned on the impeller so you know how to place the new seal. It is possible to place this seal upside down. Note: You may have to also have to remove the metal collar if the new shaft seal also has one. Several people have written in saying that the new seal won't fit because they were trying to place the new collar on top of  the old one. DO NOT touch the bearing (top) surface of the seal. It can corrode the surface.

Step 16

Push the the half of the seal that you just removed onto the new impeller. Make sure the new seal on in the same postion noted above. Again DO NOT touch the bearing surface of the seal.

Step 17

With the wrench securing the back end of the motor shaft, screw the impeller back onto the shaft (clockwise). Hand tight is sufficient.

Step 18

Replace the capacitor on the backside of the assembly. Make sure the plastic strip is in place between the clip and capacitor so that the capacitor does not short out.

Step 19

Replace cover and secure with two screws.

Step 20

Inspect the diffuser gasket for wear. Replace if required. Put a thin coat of lubrication on the gasket.

Step 21

Snap on the diffuser - no screws are required. Ensure that the part of the diffuser labeled "TOP" is aligned with the "TOP" labeled on the seal plate.

Step 22

Slip the motor assembly back into the housing.

Step 23

Replace the four bolts evenly. If bolts were numbered 1 though 4, replace bolts in this sequence - 1, 3, 2, 4 - to ensure that the motor is set properly inside the housing. Loosely tighten bolts in this sequence, then go back and tighten them down again in this sequence. If pump has 6 bolts, replace bolts in this sequence - 1, 3, 5, 2, 4, 6.

Step 24

Prime pump by removing strainer lid and filling strainer with water. Replace lid.

Step 25

Reset circuit breakers and start pump.

Step 26

Close the relief valve on top of the filter, after the air is purged and water starts to spray out of the valve.

Comments (1 to 27 of 27)

Add Comment



User: Inyopools

Smitty - If this is the first time you have run this motor, it may be configured for the wrong voltage. Check your incoming voltage. You may have 115V at the breaker box and your pump may be set up for 230V.

User: Smitty

When turnin the pump on, the motor runs at a slow speed for the first 20 seconds, then it shuts down completely. Any advice?

User: Inyopools

dlc - If your motor is not making excessive noise, it and the impeller are probably not the problem. And if your impeller was clogged, you would not have good flow initially. I would guess this is a filter issue. If you water was dirty and you ran that water through the filter, the filter may need to be cleaned several times to clear the fine debris out of the filter. If you used chemicals to clear your water, these chemicals may be clogging your filter. Try soaking your filter with a TSP solution to help clean out the fine residue in the creases of the filter.

User: dlc

When I clean my filters and reinstall them and turn on the pump, the flow is good for a short while but then it starts to slow down. I have a filter that is a little larger and it works better. I was wondering if the pump could be losing flow when the back pressure in the filter starts to increase due to problem with the impeller. I do not believe it is the filters one is 6 months old and it does the same thing. the flow starts slowing down about 2 hours after the pump is restarted.

User: Inyopools

loss of prime - If you are truly losing prime to the point that your pump can no longer suck in water - no water flow, you may have a leak in your vacuum hose. Try disconnecting all hoses except the one coming out of the skimmer. Make sure that hose is completely under water. Your pump should maintain prime. Add the rest of your hoses without attaching the cleaner. Hold all of the hoses under water. Again your pump should maintain prime. Now add the cleaner and let the hoses float to the top. If you lose prime now, you have a leak in one of the hoses. Check hose connections then take out one hose at a time to try to isolate the leak.

User: 

My Hayward super pump loses its prime when I attach the pool vacuum at the skimmer. The pump doesn't seam to have the suction power when the vacuum is connected. What could the problem be?

User: Inyopools

ds1 - If you have a leak between the impeller and motor, you probably have a bad motor shaft seal. I would take the motor out of the pump housing per the above instructions. Then check that the impeller is sound (is not cracked or wobbles) and not clogged. Then rotate the impeller. If the motor shaft does not rotate freely, the bearings are probably bad. Most people replace the motor when the bearings go but they can also be replaced with the right tooling.

User: ds1

I purchased a new above ground pool with a 1 1/2 HP 2Sp pump, last year. I drained for the winter. After reinstalling hoses and pipes, there is a leak between the motor and impeller. There is also a loud noise coming from the motor. Any suggestions? Do you think it's a bad bearing or a pump seal?

User: InyoPools

mckyd68 - Sounds like the bolt is stripped. Try putting some pressure under the head of the bolt with a flat screwdriver as you are turning the bolt. If the bolt or socket is stripped, you may have a problem getting it to hold when you reassemble your pump. Talk to a local hardware store about your options or you may be at the point of buying a whole new pump.

User: mckyd68

I am trying to remove the motor on my Hayward Super pump. One bolt just keeps spinning and is not losing up. Any suggestions?

User: InyoPools

kfcrandy - The impeller is not your problem unless it is clogged. See our guide on cleaning out an impeller Also if you have low pressure, you may have developed a suction leak in your pump or in the piping coming into your pump. Finally make sure that your skimmer and strainer baskets are clean.

User: kfcrandy

My pump ran dry due to my pool running low on water and now it has very low pressure, will replacing the impeller be the fix I need to regain the pressure I need to filter the water...?
Thanks, Randy

User: InyoPools

stuck motor - Most pumps come apart easily. If you have an old pump and it hasn't been pulled for a while, it may be corroded shut a little. Try hitting around the joint with a rubber hammer. If something is jammed inside, you may have another issue. Try prying the motor out gently. Have a new housing gasket ready if you have to put this together right away.

User: 

Unbolted the motor to check the impeller for trash but couldn't pull it apart. didn't try to force it. Is it necessary to pry the motor away?

User: Happy Canuck

Your page on how to clean the impleller just saved me buying a new pump. I have owned a pool for 25 years and thought I had been through it all. I was wrong. Thank you again!

User: marcy

pump is making loud noise/I have a 1-1/2 hp power flow Matrix pump...had it for 4 yrs.I bought it off my boss.he had it for 2 then now I have it.please help

User: InyoPools

impeller - An impeller works against the water so it is self-tightening. Hand tightening is sufficient. You can break the impeller if you over tighten it with a wrench on the impeller end.

User: 

Can you over tighten the impeller to the shaft how do you know when you have over tightend?

User: Ian Carucci

Wow I almost bought a new pump, unclogged the propeller in 5 minutes!!
Thank you!

User: 

Thank you so much for this information!! Our impeller clogged up & only hummed when we turned the motor on. Your instructions were so easy even a girl (i.e. me) can do it!! Thanks Again!!!

User: Daveo

Excellent information. Your how to instructions definetly saved me time and money, and avoiding costly wrong installation errors.

User: InyoPool

John - This is a problem on our side. We are in the process of correcting this printing issue but in the meantime try this. Copy the 6 six pages, move them to Word, and print the guide from Word. That has worked for me.

User: 

How to replace a pool pump impeller, pages 1 thru 6: Only page 1 is viewable in print review and the only page that prints. Pages 2 thru 6 print but none of the information viewed on the screen for these pages prints. Can you tell me why or if I am doing something wrong, please. Thanks

User: 

People, save some money and replace your pool pump impeller. Thanks for this information my pump is up and running.

User: 

Thanks very much, impeller was clogged. Took me 2 minutes.

User: mark

saved me a lot of money and was very helpful.

User: Larry

Thanks for your help....

Back To Top

Tips & Warnings

Remember to turn off power to the motor at the circuit breaker prior to working of the motor pump.

Do not touch the white ceramic surfaces of the shaft seals during installation

Short out capacitor before handling to avoid shock.


Please Note:

Inyo Pool Products is not responsible for any injury or damaged equipment
while using our guides. Using our guides is doing so at your own risk.
These guides are suggested use of your pool or spa equipment and may vary
depending on which product you are using.