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This sounds like two different issues. Do you have a small digital multimeter for some testing?
I would begin by making sure that you didn't miss a GFCI outlet someplace. Having multiple outlets off at the same time usually points too that. Then take your meter and check the output AC voltage from each of the breakers and see if one is bad or tripped. Lets get the AC side solved and then move to the DC issue.
A/C power or DC power to the water heater? And there are at least two GFCI outlets.......one may be in a compartment or sort of hidden. Does the water heater have a separate breaker? How did the breakers test out?