Originally Posted by BobHanke
Electric heating element only needs AC.
Originally Posted by TURBS
For the heating element you need 110v for the heating element and 12v for the circuit control board.
These statements could be true or false depending on which model Suburban the OP has.
1.If he has the model (ex SW6DE), with only an outside switch to turn on the electric element, then there should be no need for DC.
2.If the OP has a Suburban model (ex SW6DEL) that also has an inside switch for the electric element, then this switch is 12 volt powered too, and goes into a relay that turns on the 120 volt for the heating element.
#1 from Bob Hanke seems to be the more common Suburban water heater in the Forest River products and where I would lean towards unless told different...... but there are also #2's which Turbs currently has (as I personally know he has the inside switch for his electric element in addition to his DSI switch).
So without knowing for sure, it could be either/or.
The wiring schematic for #1 can be found here:
Suburban's electric switch and much more
and the wiring schematic for #2 can be found here that shows the 12 volt wiring before the relay, and the 120 volt wiring after the relay:
2015 Stealth 2313 water heater problem