Aquamanta Efx 300 Problems

[Ri-Za]

Hi all

So I bought an aquamanta efx 300 a couple of months ago and I was doing a regular clean out the other day but after sticking everything back together the filter doesn't seem to work. I've stuck everything back together as it should be and checked multiple times but for some reason the outflow won't work. The water sucks in fine and there is a good intake but once the filter reaches its capacity it doesn't seem to go through the out pipe back into the tank.

Has anything else had this problem and what is the best way around it?

Thanks!