We live in a mobile home. The water heater is located in an outside area, but is blanketed and has a door to help insulate. The wind blew the pilot out overnight and there was no hot water in the morning when the hot water faucet was turned on by itself. However, we can turn on a cold water knob in a bathroom sink and then turn on hot water knobs to other faucets elsewhere and water runs through them all, but it is not hot and the water heater now seems to be up to temp. I thought maybe the cold water somehow acted like a vacuum, but I don't know. After running water that way for awhile, it never got hot. Husband says that it is somehow pulling the cold water back through the hot water turn ons.?

Sounds like the hot water line between the water heater and the house is frozen. When you turn on the bath faucet and then open the hot side of another faucet, the cold water in the bath faucet will flow to the hot water side and then come out the other faucet because there is no pressure on the hot water side of the system.