By Pentair Pool Products



Part # 5055-12A

Manufacturer Code C1-271P

Dimensions 7" x 1-7/8"

Alternate Part #'s 35-102-1161, 351021161, C1-271P, C1271P, PENC1-271P, STA-101-8556, STA1018556, PENC1271P

Product Description


Frequently Bought with this Diffuser

Diffuser O-ring 5055-13

Magic Lube O-ring Lubricant

Used with the following Models:


?     Asked on 8/21/2017by donna

Will this diffuser operate in a Sta Rite P4RA6G-188L pump? Do you carry the matching impeller? Thanks

A  Answered on 8/21/2017 by InyoPools Product Specialist Lennox H.

Hi, Donna. Yes, this Diffuser - C1-271P along with the Impeller - C105-238PDBA will fit the Sta-Rite P4RA6G-188L model pump. 

?     Asked on 10/9/2017by Roman

Good Day! I have two questions I have seen an imaging of the diffuser without brass ring. Is it real diffuser? Can it work? Thank your answer...

A  Answered on 10/10/2017 by InyoPools Product Specialist Lennox H.

Hi, Roman. This Diffuser includes the Copper Ring. It will not work properly without the copper ring; I would not recommend that you purchase or use this diffuser without the copper ring.

?     Asked on 5/2/2019by Bruce Decker

My pump can't maintain suction on the supply line (2") and I've been told to check the "diffuser line" - to make sure it isn't clogged and that the air can escape. I've never seen such a line. Where is it? My pump is a 2hp P4 RA6G-188L. Background: I pulled the motor and impeller housing out to check for debris and that it rotates freely, and even braced it and turned it on so I could see it spin under power. Looked (and sounded) fine.

A  Answered on 5/2/2019 by InyoPools Product Specialist Lennox H.

Hi, Bruce. Pumps do not have a "diffuser line," it has a diffuser which funnels the water to the impeller. Debris can get caught in it if you pump strainer basket is damaged. You may have air in the filter which needs to be released allowing max water flow through your system. 

  • Commented on 5/3/2019 by Product Owner

    Yeah, no debris caught anywhere. I have the filter control set on "waste" so water isn't going through the sand, and earlier disconnected the pump discharge to the filter control head to make sure nothing was clogging it. (re-connected now). Do you think there still could be air trapped in the filter?

    • Commented on 5/6/2019 by InyoPools Product Specialist Patrick P.

      Hi Bruce, Did you recently replace your pump with a new pump? Or is this the same pump you have always installed in the system, if it is the same pump then did this issue just recently start to occur? If so did you make any other changes to the system like plumbing changes or installation of new equipment? Could you post us a wide shot of your plumbing set up so we can see if there are any problem areas in your plumbing like excessive use of 90's? To post photos simply click on the reply link below to upload photos.

      • Commented on 5/6/2019 by Product Owner

        Same pump that worked all last year. Just went to start it up this spring - no plumbing changes. The guys who built this were insane, trying to shoehorn all the equipment into such a tight area, with no room to work. I've never liked the 90-90 route from the skimmer line into the selection valve, but the joints appear solid.


        • Commented on 5/7/2019 by InyoPools Product Specialist Patrick P.

          Thanks for those photos! I really think the issue is the 90's those are really killing you with your total dynamic head. It may be a case where your pump has lost a bit of performance over the years and now is having trouble with the 90's. If you could eliminate one of the 90's on the suction side of the pump that would help you out a ton. I'm thinking you could cut out the 90 closest to the pump on the suction side and then lower the pipe which has the other 90 and then have straight shot into the suction port, you would need to rotate your 3 way diverter valve. Also if you could eliminate the 90 on the discharge side that would help but that looks like a much bigger project. I would suggest watching the Video we made on How to Fix Pool Plumbing Issues which does a great job of explaining the issue you are facing. One other easy fix you might try is to clean your pool filter. Let us know how it turns out.

?     Asked on 5/16/2019by yakoob

i have a P4E6G-153L STARITE maxi glass ii. Is CI-271p the correct impeller?

A  Answered on 5/18/2019 by InyoPools Product Specialist Michelle B.

Hello, In order to find the correct impeller for you, can you please take a picture of the motor label?

?     Asked on 7/6/2020by Kent Alan Lawrence

I have a Duragas/Maxiglas seal plate model number C103-137P. What model numbers of diffuser and impeller go with that? It's for a 1.5HP single speed spa pump motor.

A  Answered on 12/14/2020 by InyoPools Product Specialist Hector F.

Hi Kent, could you send us a photo of your motor? Please take a close up shot of the motor label. To supply photos simply click the reply link below and upload your photos. Once we get those photos we can make the proper recommendation.


Est. Repair Time

1 to 2 hrs

Tools Needed

Nut Drivers, Socket Set

1     0

My diffuser had a small hole worn in it after 14 years operaton.

Written on 5/24/2021 by Guest

I recommend replacing all of the seals as well since the pump is mostly apart.
1. Shut off power to the pump at the circuit breaker panel
2. Ensure the power is off using an AC circuit tester
3. Loosen the PVC unions that connect the pump to the rest of the plumbing. Keep track of the O-rings in the unions.
4. Remove the band clamp holding the pump halves together
5. Loosen the 2 stainless bolts holding the pump motor to the base
6. Move and angle the pump head away from the existing plumbing
7. Separate the pump head where band clamp came loose
8. To separate the halves, pull the strainer basket side of the pump head away from the motor. It comes straight off, but some twisting/wiggling may be required. Persistence is required but don't be rough with it. The resistance you feel is a large rubber O-ring sliding. If tempted to pry, use two plastic tools 180 degrees apart.
9. The Diffuser plate should now be visible and is retained with 5 or 6 stainless screws. Simply remove the screws.
10. The new diffuser doesn't come with a new O-ring, so reuse the old one, or if you are replacing all of the seals, use a new seal. I would use something plastic to remove the old seal, rather than something metal like a screwdriver.
11. With the diffuser off, the impeller is exposed. It's a good idea to take a careful look at it for damage. The impeller is held on with a single stainless bolt that is REVERSE THREAD, but once removed, the impeller itself is removed in the normal counter-clockwise direction.
This is just a warning in case you decide to replace the shaft seal.
12. Install the new diffuser housing and O-ring and fasteners. Don't overtighten the screws.
13. Lubricate the O-ring seal with silicone lubricant
14. Lubricate the large O-ring with silicone lube and slide the pump halves back together
15. Tighten the band clamp using the old large O-ring or a new one if you have a seal kit. The large O-ring likes to move around sometimes.
16. Reorient the pump head back in line with your existing plumbing and tighten the union rings by hand. Make sure that the O-rings for the unions are still in place.
17. Reinstall the two large stainless bolts that hold the pump to the base
18. Add water to the strainer basket to prime the pump
19. Test your work

Were these instructions helpful? 


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