Anode Rod - How long does it last?

[2011 keystone]

How long should a anode rod last?

[Festus2]

According to one source "Trailer Life's RV Repair and Maintenance Manual", the anode rod in a Suburban HW heater should be replaced "when the material (zinc) loss is at 75%". I don't usually leave mine that long and when it reaches 50%, it is replaced.
It is difficult to give a time frame for how long an anode should last. It partly depends upon your water source and the impurities that are in that water. I inspect the rod each year when the tank is drained as part of the winterizing process. They aren't that expensive and it is nice to have a spare on hand or replace it when it is nearing that 50% level.
You can end up camping in areas where the impurities in the water eat away the anode faster than in other places.

[christopherglenn]

Salt int he water causes the zinc to deplete far faster, as does water flow & water temp. Being a water heater,m it is hot whenever it is on (mostly), so turning it off when not needed will make teh anode last longer, but it is not worth it for the anodes sake, to save propane it usually is. Draining the WH when not in use will about stop corrosion (there is a slight amount due to the moisture on the rod whwn the tank is drained), it is as easy as opening the low point drains and the water valves between trips.

[chuck&gail]

They are cheap. I put a new one in every fall when I winterize.

[DEW]

I have a bit of a side question with respect to the anode. Sorry for hijacking the thread, but it is related.

When I remove it from the tank, the threaded portion of the tank has a lot of white 'scale' left on it. I assume this is because the water sat there and nothing was protecting the threads. What do you do to clean off the scale? I tried to just thread the anode in deeper to 'cut' my way thru the scale but this did not work.

Any ideas/suggestions?

[geo]

DEW -

Is that calcium carbonate scale or Teflon pipe tape? When you replace the anode, you should use "white" Teflon pipe tape on the threads, and when you remove it, there will be some "white scale" left. Try putting some vinegar on it. If it fizzes and dissolves, then it is hard water scale (otherwise known as calcium carbonate). You can use the commercial Lime-Away also, but rinse VERY well after using Lime-Away. If you can peel "threads" of it, or if it does not fizz, then it is probably Teflon. Or, if you use a dull knife or fork tine, does the "white stuff" crush and powder - calcium carbonate, otherwise Teflon.

On thread topic - when I park the Alpine for a week or more, I drain the hot water tank by taking out the anode (after turning off the pump and releasing pressure) and replacing it with a plastic pipe plug. Keeps the nasty black water from forming!

Ron

[DEW]

Thanks for the feedback. I do have Teflon tape on the anode and this is not what is left over. It must be the calcium carbonate as suggested.
I will give the Vinegar or Lime Away a try.....

[Jay Pat]

I bought a round wire brush from the plumbing dept at home depot. The wire part is about 3/4" in diameter. By hand, I run that around the treads and that stuff comes off very quick. Flush, flush and more flush! The bottom of my tank is lower than the treads....
Pat