# Hot water heater anode rod length?



## dannat (May 5, 2011)

I'm going to flush water heater and replace anode rod. I dont know what size is inside now. Does lenght have any thing to do with it except how long it would last? Heater is under warranty so do i have to but a rod from A O Smith? Also i read where they make odor control anode rods for water heaters. does anyone know if they work? thanks


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## gregzoll (Dec 25, 2006)

What makes you think that the anode needs replaced? Is it deteriorated due to the type of water, or are you just changing it for grins?


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## dannat (May 5, 2011)

We are on well water system and the heater has not been flushed in 2 years. I thought since its empty would be a good tuime to check the rod. I'm sure its worn out some, thats why i will replace it if needed. And that is why i was asking about size.


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## gregzoll (Dec 25, 2006)

Depends on the water quality.


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## dannat (May 5, 2011)

OK Lets try again. Im going to change the rod for "grins" does the LENGHTH of the rod matter. Longer is better or not and anyone heard of a rod for odor in the water?


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## COLDIRON (Mar 15, 2009)

Use a 1 1/16 impact socket with a impact wrench to loosen the nut or you'll be there all day swinging on a 4' pipe.

Order it with the model # of your water heater. Don't know anything about the smell, anode just protects the tank as far as I know.


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## gregzoll (Dec 25, 2006)

Odor removal, you have to use different filters, depending on what it is. Best to get your water tested and then work with a company to set up a plan for the various problems. There are two different Anodes, and the length is determined by model# as ColdIron stated.

If the unit is only a couple of years old, and unless water is very harsh on the tank, the rod could last for a decade or more. That means that it could outlast the actual tank.


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## VIPlumber (Aug 2, 2010)

dannat said:


> I'm going to flush water heater and replace anode rod. I dont know what size is inside now. Does lenght have any thing to do with it except how long it would last? Heater is under warranty so do i have to but a rod from A O Smith? Also i read where they make odor control anode rods for water heaters. does anyone know if they work? thanks


Length doesn't have anything to do with how long an anode rod will last, water quality does.

COLDIRON makes an excellent suggestion about contacting the manufacturer, with model # in hand, when ordering the replacement anode. Another consideration is how much height above the water heater you have as if you buy/order the solid one they can be ~3' in length. You can order a segmented one if there's insufficient headroom to make the change. See pic below.










As for the different types on anodes, here we go;

- Aluminum, used when there's hard water.
- Magnesium, the one that's usually shipped with water heaters. Used when water is soft. Not good in hard water conditions. Depending on how hard the water is may only last for a few years, with the WH soon to follow.
- Zinc, used to combat sulfur smell.


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## BigJim (Sep 2, 2008)

If this rod is eaten up will that cause you to run out of hot water with an 80 gallon tank taking a shower?


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## gregzoll (Dec 25, 2006)

jiju1943, the rod has nothing to do with running out of hot water. It is nothing more than a sacrificial element, to protect the tank.


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## myxobolus (Oct 4, 2012)

@BigJim....If the dip tube is corroded thru, that could be a cause of running out of hot water. It could no longer be pulling from the bottom of the tank.


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## Jackofall1 (Dec 5, 2010)

myxobolus said:


> @BigJim....If the dip tube is corroded thru, that could be a cause of running out of hot water. It could no longer be pulling from the bottom of the tank.


 
The dip tube is actually on the supply side, to prevent the cold water from short circuiting to the outlet side of the tank. Dip tubes are pvc or cpvc and don't corrode, they do deteriorate and have been know to crack and crumble causing the tank to short circuit.

Mark


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## myxobolus (Oct 4, 2012)

Thanks for correcting that. Not sure why I was thinking the way I was. Either way, the dip tube could still be contributing to the cold water issue.


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## chemman (Apr 2, 2012)

Or your water heater could be full of scale and is now a 10 gallon water heater. Hard water sucks!


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