Dick_B wrote:
If the bolt you referred to is the drain (for Atwood) or anode (if Suburban) it should have a hex head about size 15/16 (as I remember) and the easiest way to get it out is with a socket.
Sort of, but not quite. ;) If it's an Atwood water heater then the authentic Atwood plug socket size is 7/8", if it's an aftermarket plug it could be 15/16" ... fortunately Camco offers this handy
RV Water Heater Drain and Wrench Kit that will handle both sizes. If the water heater is a Suburban then the correct socket size for removing the anode rod is 1 & 1/16". If removing the anode rod proves to be a real bear to remove then a socket wrench with a breaker bar may be your best bet.