Just installed new water heater, turned on hot water at sink some water at first then a lot of air came out, once air stopped no water came through. Turned off tap waited ten minutes turned back on, water comes out full force, including some rust/sediment at first then runs clear for a few secs, then slows to a trickle before stopping completely. Let it sit for a while and same routine repeats, no air seems to come out for the few seconds that the water is coming out, then no water comes through. Before installing new heater I had very slow flow on the hot water side only, figuring the galvanized pipes in the slab have some blockage slowing the flow.