How difficult is it to replace the Anode rod

[paulsiu]

Hi,

After reading various article on water heaters, I have a better idea how it works. The role of the Anode rod is suppose to be sacrificial. It rust instead of the tank.

Then it's logical to replace the rod every couple of years to extend the life of the tank. I was wondering if this is something that can be done by someone who's good with mechanical stuff but has no experience in plumbing. Most articles seemed to indicate that it is difficult because either there is no clearance or the rod gets stuck due to build up.

Thanks.

Paul

[FloridaOrange]

It's just bolted onto the top. 1 1/16" 6pt socket for A.O. Smith residential units.

[kingsotall]

The consensus around here is an impact wrench is the solution.

[jadnashua]

It's the same concept as the anodes placed on a ship's hull...they get attacked before the hull does, and yes, they do need to be replaced if you want maximum life. The biggest hassle, other than getting the thing loose in the first place, is height. The average home may not have enough overhead room to get the thing out without breaking it (which isn't too bad if required). But, the new ones are available in a few configurations...one has segments that can bend, one is curved, and the stock one is just a straight rod. So, you need to know how much clearance you have. Also, depending on your water, they come in several compositions.

[FloridaOrange]

The biggest hassle, other than getting the thing loose in the first place, is height. The average home may not have enough overhead room to get the thing out without breaking it (which isn't too bad if required).

I did a high-rise project and the owners installed a building softener system without telling us so we could spec the right anode (the decision was made in the 11th hour before getting CO'd. 120 gallon water heaters in each unit and they had to pull the rod out and cut it to get it all the way out. The ended up not having enough room to put aluminum rods in. The GC made plans to eat the replacement cost of the water heaters that now no longer had any anode rods in them.

120 gallon heaters x 64 units =

[paulsiu]

So the problem is a matter of reach. I think around the heater, it's quite high, so it shouldn't be a problem.

Any idea whether to use alum or magnesium? One site suggested that magnesium is best because it corrodes slower (and the site said aluminum may be bad for your health). I notice several post on this site citing that using magnesium rod result in rotten egg taste.

Paul

[FloridaOrange]

So the problem is a matter of reach. I think around the heater, it's quite high, so it shouldn't be a problem.

Any idea whether to use alum or magnesium? One site suggested that magnesium is best because it corrodes slower (and the site said aluminum may be bad for your health). I notice several post on this site citing that using magnesium rod result in rotten egg taste.

Paul

Aluminum rods are used where some filter systems filter out chlorine (at least by my experience). When the chlorine is almost completely filtered bacteria begins to breed in the water heater on the magnesium anode rod. The bacteria generally isn't a health issue but will make the hot water have an egg smell. That's the only situation where I've ever had to spec aluminum rods.

[Scuba_Dave]

Any problem as time goes on?
These are threaded in, so maybe checking it every 3 years is a good idea?
Just to at least keep the thing free from rusting together?

[jadnashua]

You can think of the rod rusting...but commonly we reserve that for the reaction of iron into ferrous oxide. The ions in the anode literally disolve and you're bathing in them. It works by being more reactive than the iron in the steel tank. Once it's gone, the water tries to attach the next most reactive thing. There may not be much of anything left of the rod except for the stub sealing it in the tank. Some people consider water the universal solvent.

[Scuba_Dave]

I was thinking of the connection where the anode rod screws into the water heater. IE, that becoming rusted/stuck & difficult to remove. I hope that doesn't dissolve

[jch]

Magnesium is the most effective. Try one of those first.

*If* you end up with a rotten egg smell (sulphur in your water supply), then switch to Aluminum.

Rods are only ~ 20 bucks each -- the cheapest way to add years to your tanks life. If you read the fine print in your tank's warranty, you'll see a clause that says that the tank warranty is invalidated if you *don't* periodically check/replace the anode.

I've pulled rods that haven't been touched in 10+ years, and they've been easy to remove. Just use a longer socket handle When the rod material is 50% gone, it's time to replace the anode.

Does this help?

[jch]

Any problem as time goes on?
These are threaded in, so maybe checking it every 3 years is a good idea?
Just to at least keep the thing free from rusting together?

That's a great idea. Just put a label on the side of the tank stating when you last checked it.

If you have super-hard water (or a water softener), that anode can disappear within 6 months due to the amount of conductive ions (dissolved salts) in the water.

[Scuba_Dave]

Thanks
I'm not sure how old ours is
But I think maybe going on 4 years old
I guess I should also flush it out again
I meant to shut it off when we went on vacation & flush it when we got home
But I forgot

[paulsiu]

OK, I google what an impact wrench is and I don't have one, nor a compressor to drive it. Has anyone successfully do this without an impact wrench (which could be dangerous, too).

1. Use a long pipe as a lever. However, I notice that it's possible to pull the whole heater off before the screw turns.
2. Use liquid wrench on the nut, but wouldn't that end up in the water supply?
3. Use heat on the bolt, may be to break whatever sealer they use on the bolt, which sounds dangerous around a gas heater.
4. Use a hammer and a few strikes on the wrench handle to get it loose.

Alternatively, may be there's a second Anode port on the heater? Would be easier wouldn't it?

[jch]

Has anyone successfully do this without an impact wrench (which could be dangerous, too).

Yes, I've done it (on a 10+ year old tank) with just a regular socket wrench.

My advice would be to try a socket wrench first (to see if it'll work)--you might be pleasantly surprised.

If the socket wrench can't loosen it, *then* you can look for other ways to coax it loose.