Originally Posted by Oldflyboy
On the outside on the front of the heater, is a small switch that just says on/off.
Am I correct to assume that all I need to do if connected to shore power is turn this switch on the outside on and the heater would heat electrically?
Would I have to turn the inside switch on at all?
Correct. If you have only one switch on the inside with the red light, it controls the gas side of the water heater only.
The oustide switch on the water heater itself is for the electric element only.
Those two switches are completely independent of one another. You can run gas only, electric only, or both gas and electric at the same time.
Some RVs will have a second switch inside for electric as a convenience. In that case the outside switch on the water heater is the master switch for the electric element - it must be on. The inside switch is the remote switch and you can then control the electric side with the remote switch.
Finally, the electric element for the water heater should also have its own breaker in the power panel and you can also use that to turn the electric on/off - as long as the outside switch is on.