Water Heater Anode & Dip Tube FAQs
Q&A on water heater odors, anode dip tube replacement

This article gives a definition of water heater anodes or dip tubes, explains what they are for, how they work, and what goes wrong with anodes and dip tubes.

A corroded or damaged dip tube or water heater anode can cause loss of hot water, water odors, and even debris showing up in the building water supply.

A bad water heater anode can produce a sulphur odor in hot water. A worn out water heater anode shortens water heater life. A leaky water heater dip tube can cause less hot water delivery to the home or debris in the water supply piping.

What is the difference between a water heater dip tube and the sacrificial anode? Are they the same part? How to inspect, diagnose, & replace water heater anodes and dip tubes.

The articles at this website will answer most questions about residential and light commercial water heaters as well as many other building plumbing system inspection or defect topics. Page top water heater drawing showing the sacrificial anode on a water heater is provided courtesy Carson Dunlop Associates, used with permission.

Check the Sacrificial Anode & Dip Tube of Your Water Heater Tank

These questions & answers about the dip tube or sacrificial anode in water heaters and its troubleshooting or replacement were posted originally

at ANODES & DIP TUBES on WATER HEATERS - be sure to review the advice given there.

On 2018-09-10 by (mod) - risks of bacteria in water heater

Thank you for your thoughts on this, Don.

The bacteria in a water heater might be harmless as you suggest, or not, depending on the specific genera species: there are more than one bacteria that might be found in a water heater.

Common is an anerobic bacteria, also a sulphate-reducing bacteria producing H2S - Hydrogen Sulfide (rotten egg smell). As you cited, these two most-common bacteria are considered a nuisance (smelly) rather than a health hazard.

Watch out however: the assertion that water heater bacteria is necessarily harmless is incorrect and dangerous. For example, also found in water heaters is Legionella pneumophila - that causes Legionnaire's Disease that can even be fatal to some people.

See this article: Legionella BACTERIA in WATER HEATERS - at inspectapedia.com/Environment/Legionella_in_Water_Heaters.php

Bradford White, who manufacture water heaters advise these steps PROVIDED that the odor problem is only the harmless bacteria problem you described. There can of course be other sources of water odors that can also be unsafe. \

BW Recommends:

Removal of the magnesium anode and replacement with a Bradford White A420 anode rod may minimize the problem. Complete removal of the anode (magnesium or aluminum) will void the warranty and shorten tank life. - www.bradfordwhite.com/hydrogen-sulfide-odor-and-chlorinating-water-heaters-109

I agree with this very significant fact offered by Bradford White:

The only satisfactory method to control the hydrogen sulfide odor is to control the bacteria.

As a rule, public water supplies that are properly chlorinated will kill the bacteria. A private well system may be contaminated but, as a rule, it is the pneumatic tank and piping that is contaminated.

A contaminated system can be decontaminated by use of a chlorine injector or other purification systems such as ultraviolet. This will destroy the bacteria.

Their point is that the odor problem often originates before the water heater itself.

Their steps in addressing the odor are similar to those offered by articles here at InspectApedia.com

The following steps outline the proper procedure for chlorinating a water heater:

Turn off the water and power supply or gas supply to the water heater.

Drain several gallons of water from the drain valve on the water heater.

Remove the Magnesium anode rod.

Pour a ½ to 1 gallon of bleach into the water heater through the hot water outlet opening.

Install the [Bradford White] A420 anode rod.

Re-connect the hot water supply line to the hot water outlet on the water heater.

Turn on water supply and draw water at each hot water faucet in the residence until a Chlorine odor is noticed.

Once the Chlorine odor is noticed turn off the faucets and allow the bleach to sit in the water heater and water lines for a minimum of 3 hours, but a full day is desired.

After Step 8 has been satisfied turn on and draw water at each hot water faucet in the residence until a Chlorine odor is no longer present.

Turn on the power, or gas supply to the water heater.

Once all of these steps have been followed the water heater can be restored to its normal operating function. If you need to chlorinate your well system or other water system(s) consult your plumbing professional or the supplier of that water system. If you have any additional questions you can call our Technical Support Personnel at 800-334-3393 for assistance.

On 2018-09-10 by Don

Some plumbers will remove the anode to alleviate the smell. However, this means that your tank will take the brunt of any corrosion and will wear out prematurely. The other option is to switch your anode to an aluminum/zinc alloy one instead.

I got one for my Dad's house and it cost less than $50. When installing the new anode, pour about a pint of hydrogen peroxide per 20 gallons of water to kill the bacteria that cause the smell.

The smell is caused by a harmless bacteria in your well system. The aluminum or magnesium anode that comes with most water heaters promotes the growth of this bacteria the aluminum/zinc alloy will not.

You can kill most of the bacteria with hydrogen peroxide. About a pint per 20 gallons I think.

Poured directly into the water heater and then running your hot water faucets just enough to get hot water and then let it sit overnight will fix the problem for about two weeks if you do not replace the anode with an alloy one. Pull your anode, add the peroxide and install the aluminum/zinc or zinc anode and the problem should be gone for good.

If you have a salt based water softener, this will not work. The salt will negate the aluminum/zinc alloy and you'll get the smell back. In this case, an electric anode will fix the problem for about $150 plus the electric run to install it.

On 2018-03-27 01:49:53.063880 by Debbie

I just purchased a new hot water tank 40 gallon for my mobile home.

Reason I'm writing this is to ask what I should do if my water smells bad after it was installed. Do you have to keep the rod in the tank. I hear most people take them out because of their smelly water

On 2017-02-05 04:43:08.427199 by Brian Clark

I have an oil burning hot water heater. The 3/4 pipe had a pin hole. I fixed it but the pipe that went into the water tank was bad and needed to be replaced. When I got it apart a piece inside of the pipe that goes inside of the tank (long wire with ceramic on end) disintegrated in my hands.

This piece that I'm describing, I thought was a thermal cupper, but not sure. I believe it goes to the electric power box located on the outside of the tank and goes inside. It may be some kind of temperature control valve that shuts off the oil furnace.

On 2016-11-17 19:12:16.333025 by Anonymous

hi

On 2016-11-17 05:10:36.044198 by Lucretia

I am smelling a Sulphur smell coming up a duck that either comes from the gas water heater or the duct coming from my gas water furnace or my air conditioner.

Not sure what is the source of the smell but it stinks up my Master bedroom, my closet and the front bedroom.

How do I determine the source or what is most likely the source please? Note: I am not smelling any Sulphur smell in my water. Just in the wall housing the duct and in the two bedrooms. It causes me insomnia and skin rashes! Please help to give me an idea. Thank you so.

On 2016-07-25 14:38:32.823445 by (mod) -

Check for a bad water heater anode - review the article above on this page.

If the odor is also in cold water then the problem isn't the water heater it's the water supply. Search InspectApedia for SULPHUR ODORS in WATER to read complete diagnostic details.

On 2016-07-25 02:41:26.815010 by Anonymous

Sulfur smell in shower

On 2016-06-03 17:53:46.539308 by (mod) -

Mat cmmon causes of rotten egg odor are bacterial contamnination of the water heater, a deteriorated heater anode, or sulphur in the water supply. Search InspectApedia.com for SULPHUR ODORS in WATER to read details.

On 2016-06-03 13:19:34.582111 by Mat

I just moved into this house. We have a rotten egg smell from the cold and hot water. More so from the hot water but is also present in the cold water. Any idea what is causing this and how to get rid of it? My hot water tank is only 2 years old.

On 2016-04-26 06:42:15.838105 by John P Percy

When replacing the anode how do you seal the threads? Because you want an electric or ion connection between the tank shell and the anode, Teflon tape wouldn't be appropriate would it?

On 2016-02-13 21:56:19.199171 by (mod) -

Sam what type of water heater do you have: a tank heated by electricity or oil or gas, or is it a tankless water heater? If the latter, the flow rate can shut down the heater.

On 2016-02-13 21:22:40.569766 by Sam

I got a problem with my shower and kitchen sink. You turn on the hot water and cold water together and the cold water shut down the hot water.

It seems that there is no pressure at all in the hot water. same thing happen to the shower. What may be the problem?

On 2014-06-18 05:08:24.890010 by (mod) -

Have you tested the water supply for high copper content?

On 2014-06-11 15:51:58.090350 by Anonymous

The new anode has now started to show same issues. Blue flakes in the bathtub. Does anyone know what they are?

On 2014-05-19 23:55:10.088830 by (mod) -

How interesting.

It is normal for the anode to corrode or break down - it's called the "sacrificial" anode because it sacrifices itself to avoid corrosion of other higher metal critical parts in the system.

The rate of corrosion of the anode depends at least on

- water chemistry (how aggressive or corrosive is the water)

- water temperature (hotter is faster corrosion)

- water usage rate (using more faster is faster corrosion)

and in unusual conditions, an improper electrical ground can speed corrosion of components that may be inadvertently energized

But what I don't expect to see is bits of a new water heater anode showing up in the building water supply. I'd much like to hear what the manufacturer says about that question.

On 2014-05-19 23:47:53.824550 by Anonymous

I removed the anode and it was covered with blue flakes. I don't understand why it is only me. one has the same unit as my old one and he is not having any issues.

Mfg is telling me this is normal for one to deterior that rapidly. Problem is now gone. Is there any such thing as a defective anode?

On 2014-05-19 22:54:20.781110 by (mod) -

Interesting question, and I'm not sure of the answer. Some debris comes from a deteriorating plastic water heater dip tube -not what you'd expect on a new unit.

If the debris were in the water supply you'd think others would see it too.

If you can collect some water with this debris in a clean jar, take it to your local water test lab to ask what it is.

If, for example, it's copper, then something's corroding somewhere that we might want to track down.

If it's coming from water treatment equipment (like a water softener) we need to figure that out.

On 2014-05-19 21:28:05.781920 by Anonymous

I purchased a Whirpool Hot water heater in August of 2013 - with in just a few months I started seeing a blue powder residue in the tub after taking a bath. What is the residue and is it harm full for long term contact. They said it is caused by the water in Broken arrow, OK.

My neighbors do not have any issues or blue powder. My previous Hot water heater lasted 12 years and I had no residue in tube. So why is the new one leaving the blue powder in less than one year.
cwt1541@aol.com

On 2014-04-16 15:14:11.262210 by (mod) -

Anon,

If hot water is made by a separate water heater, connected in NO way to the heating boiler, then black water coming out of the tap would have nothing to do with the building heating boiler.

Check the water source at the inlet; flush the hot water tank completely, then flush the building water supply pipes and faucet strainers; then have the water tested for sediment and water chemistry by a local lab. If the water smells a bit like rotten eggs, and with a new water heater anode, there could also be bacteria in the water tank or sulphur in the water supply.

On 2014-04-16 01:44:03.354630 by Anonymous

My mother has a oil fired hot water furnace. The water heater was replaced 1 year ago because of lime build up. In October after a weeks holidays she came back to black water. The repair guy replace the anodes in a 6 month old water heater.

Water never cleared up properly, it is dirty, almost like a sediment or rust in the hot water not cold. Has been flushed a couple of times and is still dirty.

Question is it the water heater, or like they are trying to say the furnace itself. This whole system is only 10 years old. Its a rental they do not want to replace it.

On 2013-03-03 19:01:27.631292 by Ian

Is rotten egg smelling water safe?

On 2013-03-03 19:01:12.768172 by Ian

Is rotten egg smelling water safe?

On 2012-10-22 16:10:59.488096 by David Rossiter

my hot water smelled like sulpur so I had it tested and they said that my water is high in magnesium, what type of anode rod should I use to help eliminate the odour problem?

On 2012-07-16 13:26:10.258895 by (mod) -

Key,

To know what's really going on with the leak you describe I would start as you did with shutting off the water.

Now drain water pressure out of the water heater tank, and drain enough of the tank that the water level is just below the top of the tank - you don't need to drain the entire tank.

Now using a soft brush clean off all of the debris you can at the top of the water tank around the leak area and inspect what you've got - send me some sharp photos if you can using the CONTACT US link at page top or bottom and I'll comment further.

There are two likely cases:

1. the leak is bad but it's in the pipe or nipple at the top of the water tank - a repairable problem in most cases. In other words just where has the corrosion occurred that led to the leak. If the corrosion is all involving a removable replaceable anode and its threaded top fitting, you may be able to salvage the water heater - replace the anode.

2. the leak is due to corrosion around the threaded fitting welded to the top of the water tank anode mount - if this area and fitting are rusted away then the tank is not economically repairable.

Finally, if the tank is shot or even if it is to be repaired, I'd want to know why the leak occurred so that we don't ruin the new water heater tank as well.

On 2012-07-16 05:20:40.720459 by key

Have a gas ge water heater it is leaking on top of tank on anode fitting the fitting is really rusted on does this mean i need a new tank?

the leak is really bad had to shut cold water supply dont know if it is a waste of time to take anode fitting off

Question:

(June 28, 2014) Amy Prue said:

I have blackish water coming out of all faucets on a well hot and cold water. There seems to be some sediment in the water but not much. And has a kind of has a slimy texture. It also seems to come and go when running water. (being black more then clear)

Plumber took out 1 section of piping out...its still happening. he wants to change the water tank.
Please help.

What is happening? I do not want to get ripped off buy the plumber!!!
Is the water bad to bathe in?

Reply:

Amy, check your water for sulfur or other contaminants before changing equipment, but also investigate for a deteriorated sacrificial anode in a water heater tank.

...

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