to my friend from Long Island:
I think you should find out how exactly you’re getting hot water out of the tank, if it’s not being forced out by any water entering. Of course it works with pressure. Everything works with pressure (I wouldn’t get up in the morning without pressure. I’d be forever hocking away here if not for pressure) There is no “pressure from the sinks” pulling out hot water. Something is pushing it out of the boiler in the basement, all the way up to your sink.