My 6 month old Rena XP2 just started pumping air bubbles out the spray bar.
Water is not leaking out. I think it may be an internal oring leaking.
Has anyone had this happen to them??
If so, what should I look for tomorrow?
When it has happened to me I just shut it down and clean the system out. Where the intake is there is a plug. I use a pliers to carefully pull out the plug and clean it out. That has solved the problem for me in the past. Clean the impellar also. I have an XP1 and an XP2 and it happens to both, so it must be a design issue or an issue of irregular maintenance as in my case.
It suggests air is getting in between the intake in the tank and the top of the canister, perhaps where the lid fits down onto the box.
Clean everything as suggested, and add a few drops of vegetable oil to all the O-rings and gaskets. This will make them slide together easier and not catch. If this does not solve the problem you can try using petroleum jelly or plumber's silicone on the O-rings. If this fixes the problem it is only a short term fix, better order new O-rings.
Also, look for cracks in the inlet tube. I had one Filstar that had such a crack, and the section with the crack was close to the top of the tank. Mostly no problem, but when the water level got low the intake started sucking air through this crack. Easiest fix: Electrical tape (yes it is fish safe) around the crack, and use this section lower in the tank.
In addition, make sure your tubing isn't too long. I thought that I didn't need to cut my tubing down and just used them with their stock lengths. And it seemed to work well for a while. But eventually, I'm assuming the resistance built up partly due to the extraneous weight of the tubing causing it to coil on itself and essentially create more opportunities for kinks to almost develop, further increasing resistance to water flow. I'm not sure how this occurred but I was bothered by what I thought was an issue regarding the filter not being sealed correctly since I could see air building up in the tube and air bubbles being expelled. I eventually cut the tubing to length and the issues regarding the air was gone.
Usually people aren't as absent-minded as me, and would actually follow directions to cut the tubing to an appropriate length! But it is worth a shot making sure that this isn't an issue.