jimleong wrote:
Fred Wilson wrote:

Anyway, we bought our house about 4 years ago and as part of the deal
had a new water heater put in. Is there a way to see this rod? Is it
something to worry with? Is it something a generally handy type person
can do?


I did just that about a year ago, on a water heater that was about 5
years old at that time. What was needed was a six pointed socket
1-1/16", breaker bar, and a 4 foot section of pipe for extra leverage.
What I found was the top 12" of the anode rod was deteriorated, but
the rest of the rod was just fine. Put the rod back with teflon tape
for easier removal the next time. I also purchased a "segmented"
replacement anode for easier installation the next time.

Just remember to turn off the gas, and the incoming cold water, and to
drain a few buckets of water from the unit before you start the
process. Go slowly, and don't force anything.


I also checked mine recently on a a gas heater that is about 5 years
old now. The rod appeared to be about half way through it's life.
I'll recheck in about 2 years.

Certainly the concept behind this is sound and well known. The rod is
a sacrificial anode, made of a less noble metal, (magnesium I think),
which will corrode instead of the tank. It's the same principle used
on every boat, where zincs are used to protect underwater metal.

I guess the remaining question is if it will in fact extend the life of
the heater enough to make it worthwhile to check and replace the anode.
It would seem that it should, because if it didn't significantly
protect the tank, the manufacturers wouldn't install them. Plus,
checking it gives some indication of how much corrosion is going on.
If you see a rod decaying away rapidly, even if you choose not to
replace it, you know that the heater is in an environment where it's
not likely to last a long time.