Water heater zinc

Submitted: Sunday, Mar 06, 2005 at 21:43
ThreadID: 121825 Views:2834 Replies:5 FollowUps:2
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Hi

Who has looked at their's? What have they found? Length of time between inspections? Any complications in removal and insertion of a new zinc?

Thanks,

Luvntravln
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Reply By: Flipp'n Lorry - Monday, Mar 07, 2005 at 07:56

Monday, Mar 07, 2005 at 07:56
I hadn't realised until recently of the need to replace the sacrificial anode - mine is nearly 4 years old, though the van would have been used about 9 months only on a cumulative basis. Just bought a new anode from Coast to Coast RV, but yet to install it. I don't think this will be straightforward as there is a lot of corrosion on head of old one.

Will advise.

Phil
AnswerID: 565968

Follow Up By: Bushtracker - Thursday, Mar 10, 2005 at 02:43

Thursday, Mar 10, 2005 at 02:43
It varies van to van, some last only a year, some last much longer, up to several years.... It is not a drama to change it over... Teflon pipe dope on the threads of the new one, and it will come out easily next time.......

Cheers, stg
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FollowupID: 844396

Reply By: Downunder - Monday, Mar 07, 2005 at 09:35

Monday, Mar 07, 2005 at 09:35
Jay,

If my memory serves me correctly Anthony posted some information on this back when we were using the old website. If you cannot find it I have changed mine once or twice and this is how I did it.

First of all turn off pumps and make sure you release the pressure in the system (taps in shower) or when you do eventually get the anode loose you will wear (under pressure) the water and whatever else is in the tank, usually sediment from the sacraficial anode.

Using a 27mm socket with extension bar and ratchet, position the tools so that you are square on with the anode hexagonal head as head surface is only about 4mm deep and it easy to slip off. Loosen anode by turning anti clockwise until it can be turned out by hand. Depending on how long the anode has been in you may need an extention bar on the end of the ratchet to loosen it. I hear some people have all mannner of trouble loosening the anode so if the extension bar does not help I would be seeking assistance from an expert.

With anode out sluice out the tank with a garden hose to remove all debris. Apply thread tape to the new anode, you only need a few turns as the primary seal is via the tapered thread on the anode and tank. When tightening do not overdo it as excessive force can split the tank housing. I'm sure there is a torque setting for this (help Anthony) but I do not know what it is, in any event it is no good unless you have a torque wrench anyway.

When I removed my first one after about 2 years it was probably half eroded away and my tank has had mostly town water through it so I imagine if you are in areas where the water is harsh it may deteriorate quicker. Not sure what the manufacturers recommendations are other than to drain the tank if it is idle for an extended period of time.

Given the complications that can arise in getting the anode out I think it would be a worthwhile exercise to remove it at least annually if for no other reason than to 'unfreeze' the thread (is that a word?) it certainly won't harm it.

I trust this may be of some help.

regards, Bill
AnswerID: 565969

Follow Up By: Bushtracker - Thursday, Mar 10, 2005 at 03:05

Thursday, Mar 10, 2005 at 03:05
Bushtracker sez....

A couple of things that may help you....
First of all, it is not harshness of the water that accounts for the life of the Anode.... This is a sacrificial anode in terms of Cathode-Anode... And in this case we are combating electrolytic corrosion.... In other words, when you are on a poor power supply and there is a bit of stray current around, what actually happens is a bit of electrolysis of dissimilar metals.... And without getting too carried away with Chemistry and Physics, the less Noble of the metals on the "Periodic Tables" of the Elements, will donate metal to the more Noble of the metals.... This stray current that carries the process from the Anode (Donor) to the Cathode (Recipient) is what we are battling with the Anode. The Anode is sacrificed instead of metal inside your water heater... This amount of stray current and how clean your power supply is on the Nuetral and Ground, will determine the life span of your Anode.... Harshness or hardness of water may deposit some calcium on the Anode, but only if it is not being worked by the process of electrolysis...

On the process of changing it, just use a bit of Teflon pipe dope, and it will easily come out next time for an annual inspection....

Cheers from the "Lone Ranger"
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FollowupID: 844397

Reply By: Tellem Bugrem - Monday, Mar 07, 2005 at 15:40

Monday, Mar 07, 2005 at 15:40
Bill, FlipnLorry and Jay,

Bill that's a perfect response. I replaced mine after 2 years...it was about 50% gone. The problem that most will have is finding the 27mm socket. Most socket sets only go to 25mm, so for those who are yet to experience an anode change, make sure you have the socket!

Hey Phil & Lorraine..........you've been counted!. My daughter was doing a traffic survey for me on 24 Feb in Tuncurry. She recorded a BT with Flipn Lorry on the back !! ....Big Brother watching......

Cheers..............Rob
Leaving on next trip soon

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AnswerID: 565970

Reply By: Rockgoc - Tuesday, Mar 08, 2005 at 05:44

Tuesday, Mar 08, 2005 at 05:44
Jay, we had a look at our's after being in Q'ld, NSW, Vic, SA, and Tassie, then WA, and after 12 months, it was hardly eroded at all. We've had some pretty hard water through it too, and bought a new anode thinking it would surely need changing, so you just can't tell!
Had to go and buy the special sized socket (Bunnings), but had absolutely no trouble with anything. There was a very detailed explanation in "On The Road" mag a while ago from another caravanner on the how-to-do-it stuff, and we just followed that. Let us know if you want a copy of the pages and we'll send them, although the other posts here are pretty good advice.
Regards, from Jan O
AnswerID: 565971

Reply By: Bushtracker - Thursday, Mar 10, 2005 at 03:24

Thursday, Mar 10, 2005 at 03:24
Bushtracker sez: Why the differing life spans of the anode and why it cannot be predetermined and should get an annual inspection...

This is a sacrificial anode in terms of Anode and Cathode... And in this case we are combating electrolytic corrosion.... In other words, when you are on a poor power supply and there is a bit of stray current around, what actually happens is a bit of electrolysis of dissimilar metals.... And without getting too carried away with Chemistry and Physics, the less "Noble" of the metals on the "Periodic Tables" of "The Elements", will donate metal to the more "Noble" of the metals.... This stray current that carries the process from the Anode ( the Donor) to the Cathode ( the Recipient) is what we are battling with the Anode. The Anode is sacrificed instead of metal inside your water heater... This amount of stray current and how clean your power supply is on the Neutral and Ground, or if you have any appliances leaking a bit of stray current onto the neutral or ground, will determine the life span of your Anode.... Harshness or hardness of water may deposit some calcium on the Anode, but only if it is not being worked by the process of electrolysis... It should just be eaten away, as minor salts in the water supply conduct stray current which picks up the metal off the Anode and deposits it somewhere else... In the case of the zinc it will pretty much flake off of where it is deposited in time.... This same process I have described is a microcosm of what is done in the "Electro-Plating" process that most would be familiar with...

On the process of changing it, just use a bit of Teflon pipe dope, and it will easily come out next time for an annual inspection.... Do not overtighten it, nice and snug, fill the threads with white teflon pipe dope, and no problem next time....
Leave the pumps off when you do the process, and water heater cold of course...
And have the replacement ready to go, and you pull one out and put the other back in without wasting water... 50% gone is still a good anode... Much less, say 25% of new and I would replace it, they are not very expensive... About $25 from memory, and can save the tank on the HWS...

Cheers from the "Lone Ranger" at Bushtracker

AnswerID: 565972

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