We've owned our 2007 Pace Arrow 36D for a a little over a year. I have no idea if the Atwood water heater (model #GC10A-4E) was ever serviced or if it needs servicing other than a flushing. It has functioned without a problem so far. I intend to buy an anode rod for it, but I can't determine if I need the aluminum or magnesium model. A dealer I contacted said that my question was a first and had no idea if there is a real difference. Any information will be appreciated.