DIYbanter - View Single Post - Question about water heater pressure relief valve is leaking

wrote:
Is tank over 6 years old? REPLACE TANK! Tank appears to be leaking at
commection where its threaded into tank. once a tank starts leaking at
a connection even fixing this leak will ONLY mean more leaks really
soon.

so why waste the $ of the valve and work just to have more leaks next
week?

That brings up a question I've been wondering about for years. Any
boater out there knows about galvanic corrosion and the need to keep
zincs on various external parts constantly under water, as we used to do
with our outdrive. I know these heaters have corrodable (zinc?) tubes in
them to allow preferential corrosion to protect the rest of the tank.
I've thought about replacing ours several years ago, but, too late, it
pretty much wouldn't succumb to the wrench and I was fearful of applying
too much force so quit. As the tank's older than 10 years and presumably
will need replacing in the near future, my question. Have any of you
folks replaced the anode in your tank, and comments on whether you feel
that lengthened the tank's life? I guess the answer would have to be
somewhat subjective, but maybe there's some info. someplace on the 'Net
to indicate whether it'd be worthwhile to give a look see.