When to replace Anode Rod (water heater)

[Yosemitebob]

OK, so I drained my heater today and I noticed that the rod was almost eaten up right close to the threads. I've only had the trailer for 3 months used it three times. Should it be almost gone already, this quick? I book said maybe in 6 months. I've had other RVs so this is not new to me, but this certain issue is new to me.

[SAD]

Varies with the quality of water you've had in the tank.

Replace by visual inspection rather than by time period.

Can you post a pic of it?

[Yosemitebob]

I will have to wait until I get back over to the storage yard. I think I will buy another and replace anyway.

[JRTJH]

There are, I believe, two types of anode rods. One is the Suburban OEM rod, made of a magnesium alloy and the other is an after market anode made of an aluminum alloy. The "claim to fame" of the after market anode is that it lasts longer than the original anode. This may well be true, but when you consider that if it's not being "consumed" as the sacrificial metal, then the metal that is supposed to be protected is being corroded away.

While it may "seem thrifty" to buy an after market anode that lasts for several years, I'd have to ask what is being protected and what corroding away in the water heater? I wouldn't put my water heater at risk trying to be "thrifty" by buying an anode rod that doesn't deteriorate.

Something to think about, eh?

[Yosemitebob]

Now that is good to know, as I was looking at the 15.00 alum over the 20.00 mag. I think I'll opt for the better one, thank you.

[jerseyphil]

Originally Posted by JRTJH

There are, I believe, two types of anode rods. One is the Suburban OEM rod, made of a magnesium alloy and the other is an after market anode made of an aluminum alloy. The "claim to fame" of the after market anode is that it lasts longer than the original anode. This may well be true, but when you consider that if it's not being "consumed" as the sacrificial metal, then the metal that is supposed to be protected is being corroded away.

While it may "seem thrifty" to buy an after market anode that lasts for several years, I'd have to ask what is being protected and what corroding away in the water heater? I wouldn't put my water heater at risk trying to be "thrifty" by buying an anode rod that doesn't deteriorate.

Something to think about, eh?

Excellent logic. Thanks for that insight.
I'll stick with the OEM rod.

[Papa Puttz]

On my tank the anode is about 8 - 10" long, also the anode was threaded into the plug. I removed the anode and cut off 1", rethreaded anode and installed it back in to plug and then back into tank. Saves on buying a new anode.

[Yosemitebob]

What is it that attacks the rod, would filtered water do the same?

[Festus2]

The water in the HW tank reacts with dissimilar metals (tank linings) which results in an electrolytic reaction. This reaction will, if there is no "sacrificial anode", corrode the metallic sides/innards of the tank. By having the anode inside the tank, it becomes the "target" of the corrosion rather than the tank itself. Some tanks, depending upon the type of metal used in the construction of the tank, do not require a separate anode.

Corrosion increases when the water temperature increases and also when there is a higher content of minerals and other similar particles in the water. Filtered water may slightly reduce the rate of corrosion but will not eliminate it.