Help I caused a leak! Understanding my multiple water heater plumbing..

So based on the advice in this thread http://www.doityourself.com/forum/plumbing-piping/546783-tapping-water-heater-supply-fridge-connection.html#post2409160 I closed the valves and started taking off the supposed vacuum breaker from one the closer tank. When water started coming out. I thought maybe that was normal and that the pressure would quickly go down it didn't. I also noticed that the cold water in pipe I was going to use for the ice maker was really hot even with the water heater off for a few hours. I then tried to relieve pressure by opening a faucet. Water came out piping hot and the other hot water tank burner kicked on which caused the cold water in pipe on the one I was working on to go cold. Of course the partially backed out vacuum breaker no longer has sealant on the threads and is slowly leaking :wall: I realized that I really don't have any idea of what's connected to what and what goes where.