Some folks replace the anode rod every year regardless of condition as part of "de-winterizing.
Others, when the anode rod has about 50% of the material still on the steel wire. (My camp)
Others wait till its almost all gone.
Ac to the AC water heater. Look outside under the drop down cover and look in the lower left hand corner (if Dometic) for a small black rocker switch. It may or may not have a safety clip through it. If it does, it is AC capable.
Note: The Interior switch with the "ON" light is for water heat on Propane only. For faster water heat recovery you CAN use both.
Never run the water heater without water in it. ALWAYS turn the element off when you do not plan on using AC for water heat.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW