I filled my tank enough so that the intakes on my 2 XP3 filter were well below the water line. I thought the Rena's would turn on then automatically start filling then start working... well they aren't filling, needless to say working. How do I get them started??
You can not just turn them on without being full of water. What you can do is to take the cap off of the intake and use the funnel to fill it up. This method would take quite some time though. I think where your issue is that there is still not enough pressure above the intakes to fill up the canister. Once the canister is full and all air is out of the lines as well as the canister, it should flow fine and you can power them on. Another option you do have is to fill it up before you even put it under the tank. Make sure the water matches in temp and in de-chlorinated if need be. Finally what I do sometimes is to unlatch one of the hooks that hold the motor on the canister and gently pull up to allow the air to escape there and then quickly latch it tight once all of the air is out. Hope this helps.
Sounds to me like the output tube is full of water and the water that is trying to come in the intake cant push it out to fill the canister. You have to fill it with water before plugging it in. If you dont you will burn up the motor. Try lifting up the latch on the hose connector, fill the intake hose with water at the screw on cap, then push the latch down on the hose connector. If that doesnt work, you need to get the water out of the output hose.