Originally Posted by BuckeyeChuck
Not all hot water heaters have the electric option. If yours does there should be a switch inside the camper that will allow you to either run it on AC, gas or both. If no switch you PROBABLY have a gas only water heater.
While it is true that you MAY have an inside switch for the electric heating element option, MANY of the RV's equipped with the Suburban water heater have the electric heating element switch on the front of the water heater itself (which is accessed from the outside of the RV). All three of my RV's had the inside switch for the gas portion, and an outside switch for the electric portion. See Turbo's pic in his previous post.
So it boils down to, you may or may not have an inside switch for the electric heating element portion of a Suburban water heater.
This link may help if you have the Suburban water heater in your RV.