Atwood Water Heater - anode rod found when winterizing.


2016 Unity MB
Being a new owner of a 2016 Unity MB still very much at the newbie stage :rolleyes: my stocked tool box is getting good use...
As per the title, I have a question about the Atwood Water heater as I found an anode rod when I took out the plug. So first how I got there:

Winter is fast approaching so I was winterized the unit today. I first watched the LTV video and did a lot of reading and took notes. All went well with a few things learned. LTV even provided a link to download the video so I could have it on my tablet that does not have DATA/Internet access.
Some Notes:
1. When dumping the black tank there was no water hose with a nozzle at the only sani dump that was still open. so went by sound of the pump and had balanced the grey tank levels to add water so went with "hope for the best". When the monitor says 0% that does not mean it is completely empty. But thankfully it was not much before the pink showed up via the macerator pump. Finding a place which has water to flush the tank is now a must on the Winterizing list for next year.
2. I could not find anywhere the amount of anti freeze needed. so only got the smaller 1 gal (3.78Litre) container - a good thing there was a supplier 5 min away.
Now the question:
3. The plug from the Atwood Water Heater; model GC6AA-10E uses a 22 mm socket not the 1 1/16" as mentioned in the LTV winterizing video. A pair of adjustable pliers worked to get the plug out as I only figure out the size after I took it out. the pictures below is what I found. I also found a plastic plug that had been left behind. It fits where I took out the metal plug/anode rod so I temporarily use it to plug the hole.

I have read lots on a few different forum that says with an Atwood there is no need to have an anode rod.
So should I look to replace the anode rod that was already there or should I just use the plastic plug?
If I only use a plastic plug I would get an extension to my fill hose to spray around the tank next spring.

The anode rod that needs a 22mm and the threading that fits is not the easiest to find so a part # would be appreciated if it a good idea to put one in again.
From what I could find it looks like it might have been a 4 1/2" rod?
I also read that the plug should be plastic and have a spare. If it is metal like the one I took out, it sound like it needs to have an anode rod as it is introducing a new metal, different then the tank metal (aluminium). ?

Thanks you for the help you may offer.
Anode Rod side.jpg anode rid froint.jpg

Aqua Puttana

Poly - Thread Finder
"If you have a Suburban water heater, the tank is porcelain-lined steel and requires an anode rod to prevent corrosion of the steel tank. If you have an Atwood water heater, your water heater tank is aluminum and does not require one."

"Important Note: We have read about Atwood water heater owners who have installed anode rods in their drain plugs to prevent the steel threaded drain insert from corroding. This has been reported to be a source of potential leaks as the steel drain insert can eventually rust."

My comment.
I don't know why a steel threaded part would be used in an aluminum tank.


Scrolling down in this link...
Attwood responded here that a rod is not needed.

Anode for Attwood
by: Toober

I contacted Attwood and they told me they recommend against adding an anode to their tanks due to electrolysis of dissimilar metals.

My comment.
If you don't have any steel involved with the tank then an anode rod is not necessary. (The threaded boss on my RV trailer hot water tank was aluminum, not steel.)


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Unity 2016 TB
My Atwood water heater on my 2016 came with the plastic plug. I remove this to drain when winterizing and replace it after draining the tank. Mine has never had an anode.


2016 Unity MB
I wonder what else the previous owners did that i might have to undo. đŸ˜•
At least, whoever made the change to the anode rod did not throw out the plastic plug (-:
Thank you for confirming my suspicions.


Unity 2016 TB
BTW, you can get those plastic plugs at any trailer or RV store. They are very common. I bought a pack of 2 as spares. Before I found the right socket to fit mine I started to round it off a bit.

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