Water Heater Protection
 

A short time ago, someone, possibly Rich, mentioned that there are water heater plugs with finger petcock drains that could be installed in place of the nylon plug that Atwood heaters have as OEM equipment.

Well, a few years ago, I think maybe near the end of 2011, I bought and installed a sacrificial anode rod with such a drain. I found it at Ace Hardware.

It seemed to work fine, although the petcock became rusty looking very quickly.

This year, when I opened the petcock, only a small amount to water dribbled out. And, I decided I should probably flush the tank with my tank cleaner wand that I bought some time ago and have never used. :o Sometimes, my brilliance astonishes me.

So, I removed the plug and rod assembly and you can see from the pictures, it has certainly suffered. Additionally, at least two gallons of water (maybe even more) gushed out of the drain with the plug removed. I think I was lucky to have removed it now. Clearly, the petcock drain was blocked and you can see the anode rod is in danger of falling apart. Yow! There are two small holes near the threads (you can see one in the second picture) that are there for draining purposes. They won't allow any large particles to pass through, so sediment could easily build up in the tank.

I recalled that shortly after I installed the anode rod, I read somewhere that it was not a good idea to do so in Atwood water heaters (the brand that's in my trailer). I sort of "ignored" that advice then (obviously) so today I did a search for information on using this product. I came up quickly with these two links:

https://www.rv.net/forum/index.cfm/f...print/true.cfm

https://www.hilotrailerforum.com/f17/...r-brands-1835/

I think it was the second source that I read then, in our very own forum.

Anyway, I've decided I'm through with anode rods and metal plugs. I still have the nylon plug (I never throw anything useful away) and it will be going back into my heater.

- Jack

A good lesson for all of us, Jack. I think I had a Suburban water heater which used the sacrificial anode rod on my Lazy Daze so I was a little surprised that the Atwood does not require it. That's a good thing though- less maintenance! :)

I was considering adding a brass valve to the drain hole but have since reconsidered. I would rather sacrifice the nylon plug rather than risk cross threading or causing bimetallic corrosion to the (assumed) aluminum threads on the tank drain hole!

According to "Everything About RVing" the reason an anode rod is used in the Suburban water heater is because the tank uses enamel over a steel tank. If the enamel cracks for any reason, it will expose the steel to the water and the steel will start to corrode. The anode rod attracts the corrosive elements in the water that could corrode the tank. The water tank on the Atwood water heater is made of aluminum which does not have the same corrosive properties as steel. Thus no anode rod needed for the Atwood. Hopes this info helps.

Bob

Jack, thanks for the follow up on this. I was in a hardware store yesterday and today looking for the drain plug you had installed, but could not find one for the 1/2" outlet on my Atwood. Will look no more.:D

Jack,

Other than the valve being corroded that anode looks exactly as it should after being in service. Anodes are sacrificial. Basically they corrode so the nobler metal they are protecting will not. As a result anodes need to be replaced periodically.

The anodes on my boat's heat exchangers look much like yours when I remove and replace them every year.

Thanks, Raul - I know the anode looks "normal" after being in service. My point in posting this thread was to share my mistake in leaving the thing in the water heater for several years without checking it, showing how much it had degraded. I think I was lucky to get it out in one piece. And, by leaving it in, I was not flushing the heater after use during a season.

Overall, I am guilty of very poor maintenance and I wanted to help others avoid my errors.

Since the Atwood heater is made of aluminum, it does not seem to be subject to the kind of galvanic corrosion that a steel walled heater would be subject to. I believe the anode rod will corrode, in water, regardless of the design of the surrounding container. I suspect it would do it even if submerged in a glass bottle. So, it did its thing, but from everything I've read, it was not needed or helpful in an aluminum tank. And, I think it could potentially be a problem if left in place for an extended period, which is what the petcock drain made me think was normal.

If I had a Suburban water heater, which DOES need an anode rod, I would NOT use one with a drain valve.

- Jack

Jack,

Did you use teflon tape when you installed the anode. I think that would help to remove the anode. It may be best to put the nylon plug back in.

Hi Rich. No, I just used teflon paste. It didn't leak and actually unscrewed quite easily, but, because of the deformation and accumulation of deposits on the anode rod, it "caught" slightly in the opening when I extracted it.

I'm not a huge fan of teflon tape. I've often had leakage when using it, but have never had problems when using the paste. Sometimes, I use both, and that works fine too.

My real error was in leaving the rod in the heater for so long without checking it. I was thinking that since the heater is used so rarely, it would not degrade so quickly. And yes, the nylon plug is back in the heater now.

- Jack

Anode
 

I too have replaced my nylon tank drain plug with a water heater plug with finger petcock but it does not have an anode rod on it. I find it to be a lot easier to drain the tank than having to remove the original nylon plug. I never have had a problem with it getting clogged and not draining.
God Bless
Papa

I just use the nylon plugs. Did my winterizing last weekend - and I left the plug in after I drained the tank. Usually I leave it out - but I can't remember why. So what do the rest of you do? Leave the plug in or out while the camper is n storeage mode?

Plug
 

hilltool,
I can think of two reasons to leave it installed.
1st. keeps critters out.
2nd. Next year I'd forget where I put it. ha
God Bless
Papa

Having just gone back to the nylon plug, I reinsert it and turn it about one thread so that it is very loose and not watertight. This allows any additional water to drain, prevents any pressure buildup and, as Papa said, keeps the critters out.

I tighten it when I get the trailer ready for the first camping trip the following spring.

- Jack

I used to leave it out and let it just sit in the compartment until I realized that could be an annoying mistake if the door inadvertently opened and the thing bounced down the highway somewhere. However, this thread made me start worrying about water "left in the tank" ----but then I realized it must not be a problem as I have just drained everything in the past and never worried about it-and had no problems- through three Wisconsin winters.

I sadly packed her away last weekend but we are hoping to try the "snowbird thing" this February for two or three weeks----Florida or Texas. So- I was hoping to winterize it so I didn't have to worry about the antifreeze once I was on the road. But, I ended up blowing out the lines AND running a gallon of antifreeze through everything as it was pointed out to me that blowing the lines doesn't necessarily get to the toilet valve nor does it get the pump protected. Ill just drive far enough south if we take off until I can get to a fancy campground one night and flush the lines- Sometimes I can over think things. :)

Rick

I've done this mod to three RVs and never had any issues with corrosion:

https://www.hilotrailerforum.com/f27/...allation-2903/

I remember you posting that before, Raul. Nice mod!

As for leaving water in the bottom of the tank I have a hose end valve and reducer to 1/4 " tubing and rinse it out at high pressure when I winterize and before the first trip. In 1993 I bought a Truck camper that had sat with water in it for some time. When I pulled the plug and rinsed it a big glob of ... something... flopped out. I think I used bleach and rinsed it 20 times.
Removing the nylon plug is pretty simple with a socket on my TowLite.

After draining the water heater tank, the amount of water remaining in the tank will not be enough to damage the tank if it freezes. There is plenty of room for the water/ice to expand and not damage anything. If you did not drain the tank and the water freezes, count on replacing the water heater tank or the heater itself. One of our club members found out the hard way.

Bob

I leave it in so unwelcome critters don't crawl in. I do the same with the fresh water tank drain, I close it to keep other critters away.

According to my Atwood manual, the issue with the remaining water was not related to freezing but to corrosion.

Does anyone know if a 1993 classic atwood heater requires an anode rod? Im getting conflicting information but majority would say no, as atwood is made of aluminium... ?