Rheem sacrificial anode that doesn't "sacrifice" itself?

[x-ray]

Our Rheem hot water tank was installed in 2019 so I considered this to be time to replace the anode rod. I was astounded to see that the anode rod had not sacrificed itself at all. Being a simple, passive (non-powered) rod, it seems obvious to me that this means it is entirely ineffective. I left the old installed and decided to research this matter.

what's going on?

I don't know the type of material it contains. since I purchased a replacement (Mg) from Rheem, it calls into question the value of an anode rod from Rheem.

is there some sort of coating that needs to be sanded off? I think that would be a good starting point.

I'm planning to cut off a piece of the new one and see if it burns like Mg...

 

[Reach4]

The next time you pull the rod, check for continuity from the metal rod to the threads. Some anode rods have a resistor in line, and maybe the resistor or a connection failed. I have read that the anode rods with a resistor have a bump on top.

https://patents.google.com/patent/WO2006060024A1/en for a different anode says "The resistance can be in the range of about 5 ohms to about 500 ohms. The resistance also can be in the range of about 30 ohms to about 60 ohms."

 

[Sponsor]

 

[x-ray]

The next time you pull the rod, check for continuity from the metal rod to the threads. Some anode rods have a resistor in line, and maybe the resistor or a connection failed. I have read that the anode rods with a resistor have a bump on top.

https://patents.google.com/patent/WO2006060024A1/en for a different anode says "The resistance can be in the range of about 5 ohms to about 500 ohms. The resistance also can be in the range of about 30 ohms to about 60 ohms."

hmmm, interesting. I shall check that. Thank you!!!