? Aluminum or Magnesium Anode?

[dcmac214]

Which is better and why?

Was going to order a new anode from Amazon and just noticed they have either aluminum or magnesium available. I guess I'm bat-blind. The couple times before that I replaced the anode I got aluminum and didn't know/notice that I had a choice.

[BruceMc]

We are on a well, and the issue we've had with new S&B water heaters is the sulfer smell after a day or so. The first time this happened 15 years ago, I went back to the store & stated the issue - their reply: "Zinc don't stink!".
I replaced a second WH this winter, and you guessed it - it started stinking the next day. Back to the vendor... and now the hot water is nice and fresh again.

We have had Atwood units in our last two rigs; the fiver had a steel Suburban. I haven't had to deal with anode rods in the RV since 2010!

[Old-Biscuit]

GordonThree wrote:
Mg rod for al tank and al rod for steel(iron) tank.

Suburban RV WH is a Steel Tank with a glass-lining-----just like residential WHs

Mag anode rod is OEM
Aluminum is Option

Atwood ....aluminum tank that is alloy clad. NO anode rod used.

[Fulltimer50]

An AL tank doesn't use an anode rod. There is nothing to rust.

[GordonThree]

Mg rod for al tank and al rod for steel(iron) tank.

[GoPackGo]

I full time and the magnesium rod is about 70-80 percent eaten away at the 1 year mark. So I just replace every spring before leaving my winter hideaway.

As long as it lasts a year I will stay with magnesium. I want it to wear away and I'm worried that the aluminum version would not provide the same protection since it dissolves so much slower.

I also bought the cheap flexible hose end attachmnet which allows me to blast out all the gunk from the bottom of the tank. A side benefit to a yearly replacement schedule.

**** Do Not Forget - turn off the heating unit before draining the tank and replacing the anode. Running the electrical heater without water in the tank will burn it out.

[Old-Biscuit]

fj12ryder wrote:
I went to a magnesium rod to try and get rid of the "gel" that collects in the bottom of the hot water tank. When draining the tank last fall I noticed there was none of the nasty "gel" in the bottom of the tank to washout. Works for me.

Aluminum Hydroxide forms when water supply has high pH
Flush & change out to magnesium rod OR not.

Aluminum Hydroxide is not harmful per se......used as an antacid

[fj12ryder]

I went to a magnesium rod to try and get rid of the "gel" that collects in the bottom of the hot water tank. When draining the tank last fall I noticed there was none of the nasty "gel" in the bottom of the tank to washout. Works for me.

[Mortimer_Brewst]

I just replaced the hot water heater in our home. I bought a unit with a 6 year warranty and upgraded it by replacing the cheap plastic drain valve with a brass one. I also swapped out the aluminum anode rod for a magnesium rod. I plan on replacing it again in 4-5 years. An impact wrench makes it easy to get the old rod out by the way.
Old Biscuit is spot on with his information. Everywhere I read said that magnesium was healthier than aluminum. Here's a link for a site that has lots of info about anode rods and water heaters for the home.

[BB_TX]

I agree with magnesium. My OEM Suburban magnesium was pretty much gone after 2 yrs. Replaced it with an aluminum one. After 5 yrs it was still nearly fully intact. Did not seem to be doing much. Went back to magnesium.

[Old-Biscuit]

Suburban OEM is 'magnesium'
Magnesium provides the most protection under majority of conditions
IT dissolves quickest due to high galvanic reaction vs aluminum
IT can react with microbes and create a 'sulfur' smell

Aluminum provides good protection (Suburban Optional Rod)
It lasts longer due to lower galvanic reaction and slower dissolving rate
IT can collect calcium clumps making it harder to remove
IT can cause odors also depending on water source


Aluminum.....flat hex head on rod
Magnesium...raised teat hex head on rod

[downtheroad]

If you have a Suburban WH, I think you need aluminum.

Hopefully someone who knows what they are talking about will chime in.