xp2 canister o-ring

[chickenluvr]

Hello,
I'm looking for info about the o-ring that goes around the Rena Filstar Xp2. I ordered a replacement o-ring since the original one was stretched out. I'm still getting air in the filter, so I'm not sure I put the new one in correctly.
2 sides of the o-ring have a large groove running down the center. The other 2 sides have a small ridge running down the center.
Which side faces up?

(Thanks in advance, I realize this is kind of a stupid question!!)

 

[Daxhua]

I have an XP2 & an XP4 and occasionally my XP4 will get air trapped inside.
First make sure your plastic intake tubes are tight and check the screw on cap that is used to prime the filter.
Second, after you let the filter run for a few minutes unplug it and let some of the air bubbles out go the off the filter. Unlatch one of the latches just enough to let any air escape out of the filter until water starts to leak out, latch it back shut and plug your filter back in.
As for the o-ring, I think the groove is to create a seal around the lid that goes on the top media tray. I think.

 

[chickenluvr]

Thanks for your help, Daxhua! A member of another forum checked his XP3 for me - the groove faces the sides of the filter, while the ridge faces up/down. I tried it that way, with no leaks so far.

I really appreciate your advice for getting the air out of the canister. I contacted Planet Rena about that problem before and they were no help - they kept telling me I must have primed it incorrectly. I tried your suggestion this morning with great results. Plus, the filter seems to be pumping faster now that there's no air trapped inside.

Thanks again!