Air Relief valve leaking water when pump on and sucking air into filter when pump off


Nov 12, 2020
Hello TFP members,
I've moved into a new house with a pool and I'm a beginner so this site has been extremely helpful as I learn the pool realm and this is my first post on the site:

The air relief valve (I believe a Pentair 98209800) picture attached started leaking a slow stream or drips (dependent upon how relief valve is gently rotated) when the pump is on and when the pump turns off I hear air being sucked through the relief valve into the filter. When the pump starts back up I see big air bubbles get pushed out return lines and then smaller air bubbles continue for 5-10 mins, I think the filter is being filled with air when pump is off due to not being pressurized because of leaking relief valve? After the pump has been running 5-10 min I relieve the air from relief valve and there is minimal air that comes out and mostly water, so sounds like air is being pushed out of filter during start-up only. I see no air bubbles getting into pump basket from suction side.

-Until I can fix the air relief valve, I understand the filter pressurized with a lot of air could be dangerous for over-pressurization, so next time I start the pump (system is currently in manual service mode) would the preferred method be to try and relieve the air first that got into the filter when pump was off before turning back on pump?

-After I relieve the air from filter before pump is turned on, with the relief valve still open, I would then turn on the pump so air can disperse out of relief valve, as needed, and when water shoots out of relief valve then close it?

-Any chance pump would lose prime if I open air relief valve prior to starting pump?

As for the fix of leaking air relief, I've read on this site how to pull off the relief valve in owners manual with pulling both tabs, rotate counter clockwise and pull up on valve stem or another fix could use a garden hose through relief valve might fix the leak.

I've ordered the Pentair 98209800 air relief valve in case an o-ring fix doesn't work to have as a back up.

16000 Gallon Pebbletech gunite pool with integrated Spa; Pentair FNSP 60 DE Filter with Pentair Whisperflo 2HP WF-28 pump and Pentair MasterTemp 400 heater. Hayward GLX-CELL-15-W SWG. Polaris 3900 pressure side pool sweep with booster pump.



TFP Expert
Mar 2, 2011
Shut off the pump at the breaker, unscrew the air relief from the filter, take the air relief apart, clean and lubricate the internals, replace the O-ring if necessary.