[hamiam]

perhaps the pump you put in is not self priming. remove the hose on the output end of the pump and see if any water comes out when you turn it on. if not there is either a priming problem or an obstruction somewhere between the tank and the pump. I wud say to rip apart the pump but it shud not need to be rebuilt at its young age. I had a similar problem on one of my old boats. the "fix" was to pour water into the line between the pump output and the faucet and to open the faucet before the pump was turned on.