I imagine some readers are wondering about anode rods in FWC campers. Generally, those are
magnesium rods attached to the drain plugs of Suburban-brand water heaters. They serve as
sacrificial anodes in the steel tanks of those heaters. Atwood (now Dometic) water heaters have aluminum tanks and don't require anode rods.
FWC put Suburban water heaters (and furnaces) in their 2004 through 2009 camper models. If you go to the manuals on Four Wheel's
Owner's Manual page and click on the 2004-to-2009 FWC Owner's manual link, you'll see references to anode rods in that manual.
As far as cleaning the rod,
vinegar reportedly cleans them up. I'm not sure that makes a substantial difference in function as that's not typically what I've seen recommended. I believe it's just recommended that the rod be inspected and if a lot smaller than a new one, replace it.
I believe softened water is fine and in fact preferable to unsoftened water. The one thing I've seen that might damage anode rods is non-toxic antifreeze. Stan mentions it in the first paragraph of the winterizing procedure here:
Winter camping in our Hawk in freezing weather (post # 2)
I don't believe I've seen that concept in the winterizing videos I've watched on Suburbans but I may have missed it. We also have to consider that it may have been a recommendation at the time but that may have changed.
Edited to add:
There is one other anode-rod situation I can think of. And this one's very confusing. Camco makes a drain plug replacement for Atwoods. It replaces the plastic plug of the Atwood water heater with a petcock you can open without tools, i.e., without removing the plug. It's
Camco part number 11533. Oddly, this drain has a magnesium anode rod.
I've long wondered why the heck it has an anode rod when it's going into an aluminum tank. Marketing info doesn't answer that question. My only guess is it's there to prevent the metal threads around the drain from corroding themselves tight to the drain-hole threads.
Another odd thing about the 11533 is that Camco recommends the rod be inspected monthly. So you buy one so you don't have to deal with the plastic plug once or twice a year but you have to remove it monthly to inspect the rod?
