I have recently replaced my 2 Magnums HOT filters with an Eheim 2026 Pro and when i am trying to prime the filter for the first time, it is supposed to fill the canister with water. I have repeatedly pushed the primer and when i plug it in it just grinds. Its set up properly and I cant think of anything wrong with it Except it will NOT prime properly unless i have to push the primer button 200 times. Anyone have any similiar prolbems with this part of the filter the first time you hooked it up? thanks in advance.