Pentair CVA-24T leaking, mystery O-ring

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niwdlab

Member
Dec 28, 2022
5
Austin, Texas
I've seen other threads on problems with these actuators, which have been very helpful. One of my actuators, 1.5 years old, is getting stuck and clicking.

I opened it up, and it was fully of greasy gunky water, so clearly leaking somehow. I took the shaft & gears apart, cleaned everything up, and after putting things back together loosely to see if the gears would engage, I can see that one of them has some teeth worn down and needs to be replaced. I ordered the new gear set, and I'm hoping that will solve the problem without replacing whole unit. The motor has some rust on the housing, but appears to work okay.

One problem, though, is when I opened up the gear box, there was a small rubber O-ring, approx 7/16" outer diameter, lying on the bottom. I have no idea where this came from or where it goes, and I'm not seeing any such small O-ring on this exploded view: CVA-24 Valve Actuator (AMS1726): Compool (PENTAIR) | AQUA-MAN - (possibly related - unless I'm missing it, there's no part numbered 6 on the diagram.)

A larger rubber ring goes on the bottom of the shaft, but no idea about the smaller one. I suspect the O-ring and leak may be related. If anyone who has repaired or rebuilt these things knows, I'd appreciate any info. Thanks!
 
I'm more familiar with Jandy actuators, but they look extremely similar.

The actuator just sits on top of the valve. Unless the valve itself has a leak, there's no way pool water should get into the actuator. Rubber seals and gaskets in the actuator are there only to keep rain out. On a Jandy unit, there is no seal on the bottom valve shaft opening because it faced down, and rain doesn't flow up.

You should definitely disassemble the valve, too, and replace the shaft o-rings there. Maybe they're bad and water has sprayed out from the shaft bearing hard enough to work its way into the actuator. That should never happen.

#21 in in the exploded view might be your o-ring. On the Jandy valve there's an o-ring in the top cover, but I don't see one here.
1672297403290.png
 
Last edited:
niwdlab said:
I've seen other threads on problems with these actuators, which have been very helpful. One of my actuators, 1.5 years old, is getting stuck and clicking.

I opened it up, and it was fully of greasy gunky water, so clearly leaking somehow. I took the shaft & gears apart, cleaned everything up, and after putting things back together loosely to see if the gears would engage, I can see that one of them has some teeth worn down and needs to be replaced. I ordered the new gear set, and I'm hoping that will solve the problem without replacing whole unit. The motor has some rust on the housing, but appears to work okay.

One problem, though, is when I opened up the gear box, there was a small rubber O-ring, approx 7/16" outer diameter, lying on the bottom. I have no idea where this came from or where it goes, and I'm not seeing any such small O-ring on this exploded view: CVA-24 Valve Actuator (AMS1726): Compool (PENTAIR) | AQUA-MAN - (possibly related - unless I'm missing it, there's no part numbered 6 on the diagram.)

A larger rubber ring goes on the bottom of the shaft, but no idea about the smaller one. I suspect the O-ring and leak may be related. If anyone who has repaired or rebuilt these things knows, I'd appreciate any info. Thanks!
Click to expand...
There are two O rings on the diverter stem. Where water frequently enters an actuator is from the valve below it, bad stem O rings. Also, part 21 in the CVA-24 diagram is an O ring around the stem that turns the valve.
 
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Parts 20 & 21 are critical for the actuator. The o-ring and plastic compression ring keep dust and water from the environment out of the gear box. Make sure both are in place. I’ve rebuilt several of these, they are easy to fix. But every component is necessary and be sure to lube every o-ring up with good quality silicone. For the gear box, you should make sure all the gears are clean and free of debris. The gears should be packed with machine grease or white lithium grease.
 
Thanks for the replies. Here's a photo - the rubber & metal rings on the right are parts 20 & 21 on the diagram, and fit on the bottom of the shaft.

The tiny rubber ring on the left is the mystery one. It was sitting on the bottom of the gearbox when I opened it up. Could easily have fallen off something when I pulled it open.

IMG_2594.jpeg

Also - I'm pretty sure it's rain water getting in, the valve appears to be fine. The new gear set should arrive today, I plan to grease the gears with lithium, plastic parts with silicone, and just set aside the tiny o-ring.
 
It’s not shown in the diagram but that smaller o-ring fits in the top cover and it seals the actuator compartment by fitting around the shaft and the top cover. You need both points to be sealed or else water and dust will get inside the actuator.

The top of the actuator shaft should have the original valve handle attached to it. What style handle is the diverter valve - Pentair, Jandy, ?
 
JoyfulNoise said:
It’s not shown in the diagram but that smaller o-ring fits in the top cover and it seals the actuator compartment by fitting around the shaft and the top cover. You need both points to be sealed or else water and dust will get inside the actuator.

The top of the actuator shaft should have the original valve handle attached to it. What style handle is the diverter valve - Pentair, Jandy, ?
Click to expand...

Thanks - it's a Pentair system, picture of handle attached. I will try to figure out how that smaller ring can seal the top of the shaft, but it's much smaller than the diameter of the top of shaft where it exits the actuator cover. It could possibly fit between the handle and the shaft? The inner diameter is big enough for the bolt to go through.

IMG_2597.jpeg
 
Ok. That’s not it then because it shhoikd be the same size as the shaft.

Can you post a picture of where the control wire enters the actuator body ?
 

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JoyfulNoise said:
Ok. That’s not it then because it shhoikd be the same size as the shaft.

Can you post a picture of where the control wire enters the actuator body ?
Click to expand...

I am starting to think the small o-ring probably goes around the switch barrel. Unfortunately, as I was starting to replace the gears, I noticed the switch pins are completely corroded, and the switch just broke off the PCB. So, I will either order a new circuit board, or attempt to solder a new switch to the board, assuming I can cleanly remove the old pins without damaging it.

It's possible the o-ring was on the switch barrel and fell off while I was messing with it, or it was already off somehow indicating previous disassembly of this actuator. Somehow this thing was leaking pretty badly. I'd like to solve that problem so I don't have to deal with this again in a year.
 
niwdlab said:
I've seen other threads on problems with these actuators, which have been very helpful. One of my actuators, 1.5 years old, is getting stuck and clicking.

I opened it up, and it was fully of greasy gunky water, so clearly leaking somehow. I took the shaft & gears apart, cleaned everything up, and after putting things back together loosely to see if the gears would engage, I can see that one of them has some teeth worn down and needs to be replaced. I ordered the new gear set, and I'm hoping that will solve the problem without replacing whole unit. The motor has some rust on the housing, but appears to work okay.

One problem, though, is when I opened up the gear box, there was a small rubber O-ring, approx 7/16" outer diameter, lying on the bottom. I have no idea where this came from or where it goes, and I'm not seeing any such small O-ring on this exploded view: CVA-24 Valve Actuator (AMS1726): Compool (PENTAIR) | AQUA-MAN - (possibly related - unless I'm missing it, there's no part numbered 6 on the diagram.)

A larger rubber ring goes on the bottom of the shaft, but no idea about the smaller one. I suspect the O-ring and leak may be related. If anyone who has repaired or rebuilt these things knows, I'd appreciate any info. Thanks!
Click to expand...
Is your actuator still working? Was your board as corroded as mine too? (see bottom right corner) I just had the same issue but didn't think it was worse trying to repair the gears, especially since I couldn't figure out how to get to the bottom of the gears since the switch was tightly packed into the housing. I already cut off the cables and trashed it ... now I'm thinking I should have maybe tried repairing it after all since surprisingly electronically everything was still working fine.

20230530_182423.jpg
 
These actuators are repairable. Pentair is no longer supporting them as they want everyone to switch to their more expensive IntelliValves which are useless for most legacy automation systems. Sadly, the CVA's prices have shot up in response to this. Before COVID you could get a brand new CVA for around $120 and so it was cheaper to throw away old ones and buy new. Nowadays, you won't find a CVA less than $200 online and even more at local shops ... I had a local pool store quote me $500 for the CVA itself and an additional $180 for the tech to come out and do the Uber-complicated installations, ie, remove the old one and plug in the new one :rolleyes:

So if you have old CVA's, best to keep them and rebuild them.
 
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