Your Suburban has TWO sets of T-stats
ONE set (Hi/Normal) for 120V AC function (electric element)
ONE set (Hi/Normal) for 12V DC function (propane)
BOTH sets are pre-set disc type t-stats
HI-OPENS/Trips at 170*F....has to be manually reset
Normal....OPENS at 130*F to stop normal heating cycle/CLOSES at 100*F to allow for reheating cycle.
T-stats are located under the rubber cover with "Push To Reset" (above gas valve
LEFT SIDE-120V AC (Black Wires)
Right SIDE-12V DC (Red Wires)
You can operate either system independently or use both at same time
Electric only.....roughly 6 gal/hr recovery time (initial fill/cold water)
Propane only......rough;y 10 gal/hr recovery time (initial fill/cold water)
Electric/Propane...roughly 16 gal/hr recovery time (initial fill/cold water)
Although the 120V AC & 12V DC T-stats listed as being same set point they are mass produced and can have a +/- 5*F
So one may come on/go off before other heating system will (electric and/or propane) but if both ON then both will cause heating to occur and cycle based on their set of t-stats.
On your RV the Inside Switch is for the Propane System and the Outside Switch is for the Electric System
(Suburban OEM Electric Switch is OUTSIDE)----some RV MFGs will install a 'second' on/off switch in series inside rv for the electric---both switches have to be ON for electric function
