Hot Water Heater Anode Removal - Final Update

[Dean A Van Peursem]

I replaced my anode recently and picked up two at a local RV Dealer Parts Store. The threaded portion of the anode is much longer than previous units. Apparently other RV Owners were having similar problems. It has almost an inch of clearance now from the water heater to the hex head.

BTW, if you have imnadvertently moved the water heater bypass lever to 'bypass" the water heater doesn't work worth a darn! :-) Very embarrassing!

[HughM]

I replaced mine this weekend and noticed that the torque recommendation printed on the back of the package was 7-8 ft. lbs.
That's not much.
Hugh

[01RAMer]

Help me out here with your thoughts. Shouldn't the Anode be grounded to the tank for it to do it's job? I haven't used Teflon Tape on mine because I was under the misconception that the rod needed to be grounded for it to work. Teflon Tape would act as an insulator wouldn't it? What's the scoop on this? How does the Anode Rod work without electrical connection to the tank? Maybe electrical is the wrong thing to say here, maybe bonded is a better description.

[ols1932]

quote:Originally posted by 01RAMer

Help me out here with your thoughts. Shouldn't the Anode be grounded to the tank for it to do it's job? I haven't used Teflon Tape on mine because I was under the misconception that the rod needed to be grounded for it to work. Teflon Tape would act as an insulator wouldn't it? What's the scoop on this? How does the Anode Rod work without electrical connection to the tank? Maybe electrical is the wrong thing to say here, maybe bonded is a better description.

There is no electrical connection between the anode rod and the heater. The purpose of the rod is to provide a chemical action that draws out the bad things in the water (those things that will harm the inside of the heater). Without the rod, chemicals in the water react with the inside of the heater and cause leaks in the tank. We don't want that.

Orv

[dsprik]

As Orv said, the anode rod is strictly a chemical reaction. It is not activated by anything electrical - no ground necessary.

[ols1932]

01RAMer,
I'm thinking that "anode" rod is a misnomer. I think it would be better to call it "tank saver" because that's exactly what it does. When one thinks of "anode" you automatically think "electrical." There is another replacement part, the heating rod, which is used to electrically heat the water and that may have been what you were thinking about.

Orv

[01RAMer]

Well, I guess I'll be using Teflon Tape from now on. That will make things earier!

[bross]

You're absolutely right, the anode needs to be electrically connected to the tank in order for it to do its job. In cathodic protection, a metal anode that is more reactive to the corrosive environment of the system to be protected is electrically linked to the protected system, and partially corrodes or dissolves, which protects the metal of the system it is connected to.

I think that even if you are using teflon tape the threads of the anode will still come in contact with the tank but it's a simple matter to check for continuity using an ohm meter between the tank and the anode following installation.

[ols1932]

quote:Originally posted by bross

You're absolutely right, the anode needs to be electrically connected to the tank in order for it to do its job. In cathodic protection, a metal anode that is more reactive to the corrosive environment of the system to be protected is electrically linked to the protected system, and partially corrodes or dissolves, which protects the metal of the system it is connected to.

I think that even if you are using teflon tape the threads of the anode will still come in contact with the tank but it's a simple matter to check for continuity using an ohm meter between the tank and the anode following installation.

Local RV technicians corroborate the fact that the anode merely provides a chemical reaction to protect the tank of the water heater. They all use teflon tape on the replacement anodes, regardless of the threads making contact.

Orv

[bross]

Well Orv I hate to disagree with the local RV techs, but I worked in an oil refinery for 37 years and every tower, drum and tank in that refinery has a cathodic protection system. When those vessels come out of service for maintenance the anodes are replaced and one of the final checks after replacement is to check for continuity between the anodes and the vessel it is attached to. As I said, I doubt if teflon tape used moderately will insulate the anode, but I would defiantly check it. It doesn't do any good to have an anode melting away and not attached to the tank.

[dsprik]

That's interesting... and a new one on me. Not the first time... Would like to see a concurrence on this issue, though. Now I'm really curious.

[bross]

Here's a pretty good explanation of the whole system. The last paragraph explains the need for electrically connecting the anode and tank. http://en.wikipedia.org/wiki/Sacrificial_anode

[HamRad]

Bross,

The quote below is from the link you provided. Please note the bold and underlined section.

It would appear that the water would supply the necessary electronic link for the process to work.

Thanks for a nice link.

HamRad

begin quote
It is important to understand that for this mode of corrosion protection to function there must be simultaneously present an electron pathway between the anode and the metal to be protected (e.g.,a wire or direct contact) and an ion pathway between the anode and the metal to be protected (e.g., water or moist soil) to form a closed circuit; thus simply bolting a piece of active metal such as zinc to a less- active metal, such as mild steel, in air will not furnish any protection. end quote

[bross]

It says "there must be simultaneously present" That means you have to have both, a connection between the anode and tank, and water or moist soil in the tank.

[ols1932]

quote:Originally posted by bross

It says "there must be simultaneously present" That means you have to have both, a connection between the anode and tank, and water or moist soil in the tank.

It is my understanding that what HamRad says is true. If in fact the anode must be grounded to the tank, then why do the RV techs use several wraps of teflon tape around the threads to prevent the anode from rusting in (which it would do if the threads had direct contact with the tank) and not being able to remove it. This is directly the problem I encountered when trying to remove the original anode.

Orv

[bross]

I can't answer why RV techs do anything, I can only tell you what I know from working in this field all my life. The anode has to be electrically connected to the tank and immersed in water to form a closed circuit. Now as I stated originally, a couple of wraps of teflon tape may not insulate the anode, but if it were me, I would check it with a ohm meter after installation.

[bross]

So, the original anode that was installed by the water heater manufacturer didn't have teflon tape on it?? Hint, Hint

[ols1932]

How to win friends and influence people. I'm out.

Orv

[bross]

Sorry, if I said something to offend you, just stating my opinion.

[bncinwv]

Well, here's my two cents worth. I use teflon tape on the anode rod, but I only use a couple of wraps. When I remove the anode rod, the threads are clearly visible so if the electrical continuity is required, it is there. The teflon thread simply makes it easier to remove the rod when it needs replaced. I do agree with bross's statement based on the experience of cathodic erosion that occurs on boat drives (submerged), there is an electrical connection required because boat drive systems are designed accordingly with systems to reduce the erosion on the drive metal. Salt water is the biggest culprit but the phenomenon does occur with fresh water. This statement is not based on engineering knowledge but rather gut feeling and my personal opinion. I truly believe that a couple of wraps of teflon tape will help in removal and will not impede the performance of the sacrificial rod.
Bingo