March is water heater month

Last week I with the help of Tom replaced my sisters water heater.  Since our hot water has had an odor to it I figured I would check the anode.

An anode rod is a rod made of “sacrificial” metal.  Like batteries, the anode produces an electrochemical reaction inside the water heater.  The anode slowly wears away instead of the lining of the water heater.  As long as the anode is present and functional, almost all corrosion or rusting on the water heater tank’s lining is prevented.

If the anode rod has more sacrificial metal than exposed steel rod, then it is still in good shape.  However, if the entire surface becomes covered in calcium carbonate and this calcium carbonate becomes hard, this will prevent the anode from protecting the water heater any longer.  This is known as passivation.  If the anode has passivated, it will not look so by sight alone.  To test for passivation, you must bend the anode rod by hand.  At the bend, observe for small amounts of flaking.  The anode should be replaced if more areas of the rod are exposed core wire than sacrificial metal.  It should also be replaced if the top or bottom of the rod has deteriorated, exposing six or more inches of core wire.  An anode should also be replaced if the anode is less than half of the rod’s 3/4 in. diameter size.  If the anode has passivated, split through its length, or has become heavily pitted, it could also be time for replacement.  When all the sacrificial metal has worn away, then the steel rod will begin to wear away.  After the steel rod wears away, the only thing left will be the hex head or the hot water outlet nipple if it is a combination anode.  At this point, the water heater will begin to corrode.  If the anode is found in the above stated conditions, damage to the water heater may have already occurred.

Alright enough of the background of the anode.  Ours was down to about  1/4 – 3/8 material about 1/2 the normal size.  The anode was covered with a white material which I believed to be a coating.  I searched the local hardware store and plumbing shop and set out for Lowes.  None there either.  I got to Carter Lumber just as they were closing and had already set the alarm.  He said he did have one on the shelf but could not go back in the store.  I was a little disappointed but I graciously understood and said I would return another day.  As I was returning home I noticed all the white material was flaking off and I decided to clean off the anode before I replaced it.  We noticed right away there was no more odor coming from the water heater.  Today I was near the lumber yard and went in to purchase the anode.  I have yet to install it   Have you checked your anode lately?  They are easy to replace.  Cheap insurance against a water heater replacement, $15 vs $200 – $300.  By replacing the anode you could potentially double the life expectancy of the water heater.

BTW it’s called a water heater not a hot water heater.

\o/ Praises



  1. Posted March 15, 2007 at 1:44 pm | Permalink

    I learned something new today! Cool, thanks!

    Btw, I went and got some cash money from the ATM machine to buy an anode for my hot water heater.

    I love pleonisms (redundant phrases). Ooo … you gave me a blog idea for after Cow Week! Double thanks!

  2. Posted March 20, 2007 at 12:12 am | Permalink


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