Anode in an Atwood WH?

[SummitPond]

In another thread (water heater question (http://www.keystoneforums.com/forums/showthread.php?p=268108)) John (JRTJH) recommends removing the anode to be able to clean out the water heater. The WH being discussed, I assume, is a Suburban model, for I can find no reference to an anode for my Atwood water heater.

My questions are: If Atwood doesn't have an anode, why not? And if it does have an anode, where is it hiding?

As always, thank you for sharing your knowledge and expertise.

[sourdough]

Atwood doesn't use an anode rod due to the interior construction of the water heater. It is made of an aluminum alloy that does not require the anode rod.

[JRTJH]

Sourdough is correct. The Suburban water heaters have a steel tank that is porcelain coated. As the coating chips away from expansion (caused by heating the water) the metal tank is exposed to the corrosive minerals in the water. The anode rod is a "sacrificial" metal that corrodes to prevent more rapid corrosion of the metal tank.

In the Atwood water heater, the tank is an aluminum alloy which is thick enough to serve as its own anode, so no secondary protection is necessary. Both tanks will corrode, but with the anode rod, the Suburban will typically last 6-10 years and the Atwood, with no anode will last approximately the same time frame.

There are people who own their water heater for 20 years and never have a problem with the tank. Usually that is from not exposing it to water that has corrosive minerals suspended in it. On the other hand, there are people who on this forum who have reported having to replace their tank in 3-4 years because of leaking at the seams.

Usually the first "sign of problems" is hearing the water pump "burp" for a couple seconds at night when there is no water being used. That is caused by the gradual "leak down" of water pressure as the water heater tank seeps into the Styrofoam tank shell. Usually we never see the leak (unless it's a catastrophic leak) but once the leaking starts, it usually progresses to a point that we can't ignore the pump running every night, open up the back of the water heater and see the damp spots under the Styrofoam shell.

[sourdough]

Our Atwood died at 3 years. Had no idea but found wet spots (thankfully) around the flooring in the closet where it lives. Traced it down to a leak in the tank. One of those things that you don't think would happen in that short of a time. Seam in the tank just oozed water. Pulled it out, put in a new one and here we are. One note; when removing the heater for replacement it was obvious that the water heater is installed while the walls are still not placed. It was impossible to use the existing wiring and pull the heater then put it back - the wires were far to short for that to have ever happened. Just had to get connectors and wire and extend the "umbilical" so that it would work.

[SummitPond]

Very interesting. Something else for me to keep an eye on!

Thank you for the education.

Y'all stay warm (we may get snow by tomorrow - and this is FL!)

[shiggs68]

Here is the page from the Atwood Service Manual.https://uploads.tapatalk-cdn.com/20180103/e6b21568ead8b6e6e349ec1b0363762e.jpg


Sent from my iPad using Tapatalk

[vantage32fls]

Our local independent RV repair shop told me that you can use the anode in my Atwood tank with out any damage to the aluminum. He then showed me the anode was made by Atwood. I called our dealer and they said that it wouldn't damage the tank either. I used it for one camping season and went back to the plastic one. Any thoughts on using a anode in aluminum tank.

[JRTJH]

My way of thinking is that using an anode rod in an Atwood tank is similar to using tubes in a tubeless tire, or putting tape over each nail head in a board to keep them from working loose.

Given the "specialized construction" of the Atwood tank, I'd suppose that the anode rod is made of a similar composition, it would just add more surface that corrodes along with the tank. If it's a "more noble metal" (meaning it corrodes slower) then it would still be there, unaffected, when the tank is completely gone. Either way, it wouldn't be "beneficial" rather it would be useless or have no effect on the outcome of tank decomposition.

[shiggs68]

Our local independent RV repair shop told me that you can use the anode in my Atwood tank with out any damage to the aluminum. He then showed me the anode was made by Atwood. I called our dealer and they said that it wouldn't damage the tank either. I used it for one camping season and went back to the plastic one. Any thoughts on using a anode in aluminum tank.



What they didn’t tell you was it also will not do anything except remove money from your pocket. There are Aluminum rods sold for Atwood’s which also have an aluminum tank. Ie no advantage.


Sent from my iPad using Tapatalk

[shiggs68]

As a follow up, here is a paragraph from the Service Manual
21743