the problem could be at the pump, make sure the pump is pumping water at a slight pressure,if not the answer is with the pump. if a ok check the pipe from pump to jet for kinks,something blocking it, or an inline non return valve, which is faulty. if a ok endever to get the pipe of the back off the jet, and try again for water comeing through.if it does it should be the jet blocked. but with what you say i think your problem is before the jet.
rab, September 2012