Air flowing through returns with pump off

[Jonesbackr]

Several times a day, when the pump is not running, air will flow pretty heavily from one of the returns. It bubbles out for 3-4 seconds then stops. Pump functions fine and everything runs great with no air leakage when operating.

Is this normal or something I should be worried about?

 

[PoolGate]

Could be hydrogen gas purging from your SWCG when the pump turns off. Possibly it is getting trapped somewhere and when the trump shuts off it releases out the return.

 

[ajw22]

I wouldn’t worry about it if all is working fine.

 

[duraleigh]

It's a guess, but you probably have a suction side leak which is sucking air into the filter, pressurizing the filter. To confirm that, run your system for an hour or so in filter mode and then shut it off.

Next, open the air relief valve. If it spews out water and air, you have a suction side leak. If it sucks air in from the valve (or does nothing) it is something else. Report back.

 

[Jonesbackr]

No suction side leak. I did notice that when my filter has been off for an hour or so I can hear water flowing through the sand filter. Kind of a gurgling noise. Not sure if this means anything or is normal.