Anode rod damage to atwood tank?

[norisez]

I am posting this to attract the attention of wolfe10 whose posts indicate he really knows this topic.  All others are invited to reply, as well.

My used 2003 Southwind came with an Atwood GC10A-3E water heater, which worked OK.  Being of a cautious nature, I decided that I ought to replace the anode rod, not realiz..ing at that time that Atwoods did not require and could be damaged by one.  When I pulled out the drain petcock, there it was, an almost eaten away anode rod of unknown age.  Apparently, one of the two previpous owners had installed it at some time unknown to me.  Anyway, my question is, could this have sufficiently damaged the tank that it should be replaced?  Assume that the rod's fitting was steel.

[wolfe10]

Only real issue is "have the water tank threads been damaged.

If an Atwood nylon drain plug (i.e. under $2 each) seal the drain, you are OK.

If it does not seal, next step would be to buy and use a tap to clean the threads.

If that doesn't work, then, yes you may have to replace the tank.  But, I would suspect the likelihood of needing to do this at under 5%.

[dickandlois]

Noriser,  Welcome to the FMCA Forum !

 The tap needed to clean the treads is a 1/2 - 14 Tapered pipe Tap - The Mating Die is 1/2 in. NPT  die.

This is not a standard stock item for many location like Lowe's or Home depot.  Alfa tools is one supplier

Rich.

[wildebill308]

Welcome to the forum. If you were close I would loan you my tap. Like Brett I doubt you have any damage that can't be cleaned up with the tap.

Bill

[bm02tj]

Any hardware store should have a 1/2 npt tap 

and if unable to get one get a nipple and put three cuts across threads the use it to clean the threads 

[norisez]

Thanks all for the responses!  Yes, I am somewhat a newbie to FMCA, but not to RVing.

@wolfe10  One of my concerns is if the tank's integrity has been compromised by <=15y of galvanic action.

@DickandLois @WILDEBILL308 @bm02tj    

I will take your advice if/when it becomes apparent that the threads need chased.  BTW, would a standard nylon plug from ACE serve as well, or is Atwood using a special high temp version?

[bm02tj]

buy a PVC plug  not a soft plastic plug 

or if needed brass will work 

[wolfe10]

NO.  With an aluminum tank which the Atwood water heater has,  I would spend the big bucks (under $2) and buy an Atwood plug.  Metal plugs will have galvanic corrosion.

[wildebill308]

8 hours ago, norisez said:

Thanks all for the responses!  Yes, I am somewhat a newbie to FMCA, but not to RVing.

@wolfe10  One of my concerns is if the tank's integrity has been compromised by <=15y of galvanic action.

@DickandLois @WILDEBILL308 @bm02tj    

I will take your advice if/when it becomes apparent that the threads need chased.  BTW, would a standard nylon plug from ACE serve as well, or is Atwood using a special high temp version?

The one from ACE maynot be NPT pitch. Most plugs are tubing thread pitch. That is why you should be cautious about using the proper thread pitch. Trying to thread a tubing (brass) plug will start but will damage the NPT threads. 

Bill

[hermanmullins]

4 hours ago, wolfe10 said:

NO.  With an aluminum tank which the Atwood water heater has,  I would spend the big bucks (under $2) and buy an Atwood plug.  Metal plugs will have galvanic corrosion.

Brett is right. Atwood heater go with Atwood plug. 

Herman 

[manholt]

Ditto.........................

[campcop]

When we had an Atwood, the plug was part of annual maintenance..

[wolfe10]

4 minutes ago, campcop said:

When we had an Atwood, the plug was part of annual maintenance..

Good answer.

And flush the minerals out at the same time!

[norisez]

I think this is stll on topic, as it has drifted.

What about the brass over-pressure valve?  Or, does it have a plastic sleeve?

[wolfe10]

Good question.

Big difference is that the over-pressure valve is virtually permanent--- may have to be replaced ONCE in the life of the water heater, where the drain plug is removed at least once a year.

So thread integrity is much more critical for the drain plug.

[norisez]

Thanks,  that reassures me.  I'll fix the old one, then. Much cheaper than new WH ;-) .  And flush it, too.

[wildebill308]

We are so lucky to have Wolfe10 to answer questions. 

Bill

[norisez]

AMEN