Join Date: Oct 2012
Location: Southeast Wisconsin
Thanked 1,208 Times in 536 Posts
What type of water heater is it?
I have relit the pilot light on natural draft water heaters if there is gas on or propane in the tank. A power vent requires the gas and electric to be on.
If it's electric and the electric is on, just flip the breaker back on.
For what its worth, I don't think its possible to fully thaw a completely frozen water here in a few hours.
I have thawed and heated houses in other fashions too, but I won't post those procedures on the open forum.