Solar return making noise when pool turns off, check valve issue?

[spidey9879]

Hi everyone, had a question. I have a solar setup and noticed when the pool shuts off and the solar valve actuator returns back to the off position (moves from 9 o'clock to 3 o'clock), there is a rattling/knocking noise that lasts about 5-10 mins. I have attached a link to the video below. I recently had the actuator replaced and not sure if that is contributing or if this is a bad check valve. The solar return is above the actuator. Appreciate any help Thank you!

 

[1poolman1]

Hi everyone, had a question. I have a solar setup and noticed when the pool shuts off and the solar valve actuator returns back to the off position (moves from 9 o'clock to 3 o'clock), there is a rattling/knocking noise that lasts about 5-10 mins. I have attached a link to the video below. I recently had the actuator replaced and not sure if that is contributing or if this is a bad check valve. The solar return is above the actuator. Appreciate any help Thank you!

Sounds like the water is draining down from the panels when the system is off.

 

[spidey9879]

Thanks, is it supposed to? I don't recall ever having this kind of noise when the pump shuts off.

 

[DavidArmenB]

Is there another check valve underneath the 3-way to stop reverse flow? Check/Replace that check valve, preferably with a Jandy style flapper valve.

 

[spidey9879]

There is a 2" Flo Control valve below. I'm thinking that could be it as when the pool pump turns off, the water is coming back down through there and it likely should not.

 

[1poolman1]

Thanks, is it supposed to? I don't recall ever having this kind of noise when the pump shuts off.

Water should drain each time the solar shuts off, yes.

 

[DavidArmenB]

Water should drain each time the solar shuts off, yes.

How interesting! I did not know this.