I just replaced an old hot water tank with a new one and now this one won't heat up.
I made sure it was full and bled the air but here is my problem. It is connected electrically to a separate breaker box, there is a 4 lead wire coming out and the old tank only used two of the wires so I used the same two. The other two are wire nutted but I get no heating up of the water. There is no color on any of the 4 wire leads,by leads I mean the single wire coming out of the breaker box has 4 smaller wires in it rather than 2, there are 2 sets of breakers one is 30 amp and the other is 20 but not sure what is what. I just followed the old setup but I have no heat.

All water tanks should be on a 30 amp breaker. So if the 30 amp is not on, you won't get any power. If you have a volt meter you can check to see if there is 220 at tank.