"Robotron Tom" wrote in message
...
stated:

My son just bought an old house which has a 16 year old propane water
heater. The cold water seems fine but there is a "rotten egg" smell
which comes from the hot water. He was told that the "anode rod" is
probably at fault. Does anyone know what this is, how it works and if
it is replaceable? My own hot water heater is electric and we've had it
for 27 years, which is admittedly longer than most last but we have
very good water here. I think that he does too as I saw no evidence in
his house of calcium build up or rust stains anywhere. I know 16 years
is possibly stretching it on an appliance like this but they hardly
have a nickle left after the home purchase and anything that we can
repair we would like to. Thanks. Lenny Stein, Barlen Electronics.



The 'Anode Rod' is a metal rod, made of aluminum or magnesium around a
steel wire, which is a softer metal that will sacrificially corrode faster
than the other metal parts on the water heater. The rod is in all water
heaters and should be replaced before they corrode too far and break off
in
the tank.

You should see a steel nipple screwed into the tank on the top. Shut the
water off to the tank and bleed off pressure in the tank, then carefully
unscrew the nipple and remove it. The rod is attached to the nipple. Take
it to a plumbing store to get a replacement.

It can be removed to eliminate the rotten egg smell but it can/will
shorten
the useful life of your heater. Since this heater has had a prolonged life
the rod seems to have done it's job. Replacing the rod may well cure the
smell problem.


The manual for my water heater says that an aluminum rod can be used in
place of a zinc rod to eliminate the smell, apparently it's not as effective
but better than nothing.