Eheim 2028 filter not pushing out water?

I have an Eheim 2028, I have had it about two months and as I was doing a water change I noticed it was not spraying water. I opened the top of it and noticed the spring was caught where it closes off so water doesnt spew out when you unhook the hose. I took that out and a red cap looking thing. I guess this is the flow meter. Now it sprays a tiny bit, I try and prime it but it looks like there is not enough suction to force water out of the spray bar. I also looked in the media and it wasn't clogged. Can anyone help?