I've had an XP3 for about a year and a half. First came the trapped air it would not let go of. Then came the periodic gigantic air suck. then came the small leaks from the canister when first set up after cleaning. Then came the deafening noise as it sucked ever-larger amounts of air.
I replaced the O-rings and the seal over the impeller housing, to some effect. Then we were right back where we started.
Last night the deafening roar started again, and I was wandering around in nightclothes opening the *&$)-ing thing up and putting it all back together. Then I heard the sound no one wants to hear at 11:30 PM; gushing water.
I had to unplug it, which sucks 'cause I have an inline heater on that filter. Happily I have an HOB
filter and an extra heater on the tank.
Now I'm replacing the impeller, shaft and bearings. That makes $60-odd on parts, but I can't afford a new canister at the moment. If it doesn't work I'll be chucking it out our third-story window.
Just a "friendly" heads up! All those Eheim fanatics were right!