You can find a lot of details in my journal on this!!!
This is a fiddly filter.
1. Assuming you have set it up correctly, and all bits fitted right
2. Have the whole filter empty, or at least half empty
3. Absolutely have the prefilter tray completely empty, and not sitting in water
4. Know that the impeller does not "suck" at all. It will not pull water into the filter. The filter fills via siphon from the inlets. This is important, because if you're canister is full, there will be no siphon into it and the impeller will do nothing
5. Have both inlets under water
6. Have your outlet above water but pointing into the tank as it will spit water out. Try to have the biggest hole possible (ie dont fit the spray bar yet)
7. Avoid restrictions and low lying loops on your hoses
8. Assuming your hoses are empty to being with, connect the inlet head, and open the valve.
9. If your filter is empty, you will need to press in and out on the priming button many times, fairly quickly to get some suction going. This can take a lot of effort, we might be talking 10+ pushes maybe more, in quick succession.
10. At some point you will pull enough water through one of the inlet hoses to get over the tank side and below the water level, at which point a siphone should start. You will hear the alarming sloshing when it does. Filling the filter can take2-3 minutes.
11. Check to see if both inlet are sucking. In my case only one was. This is ok for priming but clearly needs fixing. Two ways: a) it says you can restrict by squeezing the other hose and this will lead to more pull on the other one. think this works for bubbles and airlocks but not empty hoses. b) shove an airline up into the airlocked inlet hose from inside the tank up to the highest point, and suck out the air by mouth (or pump if you have a nonreturn valve). Once you get the air out it will siphon.
12. Once your filter is full you will see water filling up your outlet hose to some degree. At this point you are good to submerge your outlet and fit your spray bar.
13. This is a fiddly filter to prime. two hoses, sensitive design with the prefilter tray. it is not always sufficient to have an empty prefilter tray.
14. Grinding / loud noises are always air lock and un primed state. No noise at all means broken or no power (unlikely); whirring means its working (will gurgle to start with while the air bubbles work their way out). If no flow but normall whirring noise most likely you have pipe blockage or the outlet duct attached directly to the impeller housing (white rubber) has come loose.
15. Once working, shake the filter a bit to release trapped air.
16. Be careful with your outlet, this thing really kicks out water.
