Just installed an ITT Jabsco solid vane driven pump as a washdown pump, but am having trouble and hope this group can isolate the problem. I teed into the raw water intake on the head. The intake runs from the thru hull then tees off for the pump about 16" up. The water intake continues to an anti siphon valve and onto the toilet. The pump seems not to want to prime, but when I pump the toilet to fill the bowl, the pump reaches pressure. If a sea water intake must have an anti siphon, does that negate using it for a pump intake for the deck? Shopuld I have teed in after the anti siphon valve?