Problems with Pentair CVA-24T Solar Valve Actuator

[jjfenton]

I started our solar system about 10 days ago and all was well, but yesterday realized there was no warm water entering the pool and the valve actuator was in the "off" position despite the SunTouch system being in the solar mode. After reading several posts, I'm pretty sure the solar valve actuator is not functioning or responding properly. Several TFPers have mentioned microswitches that may need replacement. A couple of questions:
Where are these located? A diagram of the Pentair actuator doesn't show these and I didn't see anything obvious in the SunTouch service panel.
Can I manually open the actuator valve to direct water to our panels while awaiting a final fix? There is no response when I flip from "On 1" to "On 2" on the actuator itself. Thank you for any advice.

 

[Jimrahbe]

jj,

Usually, when the microswitches are the problem, the valve will move one way, but not the other, when you move the little On-off-On switch.

I would assume that your SunTouch is not supplying the actuator with the 24 VAC it needs to turn.

I am not familiar with the SunTouch, but I would look for a blow fuse or ???

It could still be a bad actuator.. Check out this video....

Thanks,

Jim R.

 

[blac1175]

I just had a similar microswitch problem. If the CVA-24T is the same as my CVA-24, then here is what I know.

In my case, the valve would not turn at all, and that was because of the microswitch. And this seems reasonable to me: there are two microswitches, each stops the rotation in one direction, by opening the circuit when the valve core reaches the limit. When the valve rotates away from an end position, the microswitch of that end position should close the circuit back. But by this time, this circuit is not energized by the controller, since the controller is now commanding the switch to turn the other way. However, this closing back is what will eventually allow the valve to rotate back to that position when commanded so. If your switch fails to close back, the valve will still rotate away to the other end position, but will never be able to come back.

I turned off the power to the pool, disconnected the valve from the controller, and measured the resistance between the 3 wires going to the valve. Out of the 3 wires, you should find two that have ~16 ohms of resistance between them. This is the circuit the controller can energize to turn the valve. If the resistance is infinite between each pair of the 3 wires, then you likely have a microswitch issue, or the valve wires broke, or the motor in your valve burned out. In my case, it was the microswitch.

To replace the microswitches, I opened the valve by taking out these 4 screws, then lifting the cover.


Then I got to the two microswitches, each held in place by a single screw.


Good luck,
Balint

 

[jjfenton]

Fantastic, Balint -- I used your diagrams to access the microswitches and swapped them out with two SS-5T microswitches purchased online from Mouser Electronics (referenced in other TFP posts). On restoring power, the actuator immediately began to turn. In fact, it turned without ceasing, which after some quick research, I learned was probably due to malposition of one of the two plastic "arms" that engage the microswitches with the turning cam. After opening the actuator back up, I was able carefully position the two arms (these are small plastic pieces that sit between the microswitches and the cam), and the actuator began to work properly.

So thank you to both Balint and Jim. My CVA-24 is repaired and my family will soon be enjoying warm water.

 

[jjfenton]

Alas, my problems are not solved. I've noted that the actuator will only open when the cover is removed. When it is secured with the four screws, the actuator will not turn the valve to direct water to the solar panels. When I remove the cover (without turning power off at the panel), I can see a silver disc spinning underneath and the valves immediately turn, directing the water to the panels. I tried lubing up the shaft and the hole of the cover, but that didn't help. I'm now assuming that the actuator failing, as it seems to lack the power to move the valve when the cover is securely fastened.