Hot water smells like rotten eggs....

[TomC]

I also have two 10 gal electric water heaters.  They smell from the zinc anode reacting to the water to create the rotten egg smell.  Just run the water until the smell is gone.  At least you know the zinc is working.  Good Luck, TomC

[Don4107]

Maybe it is just dumb luck, but when I stopped using RV antifreeze and started blowing out my bus and boat instead I have not had the dreaded hot water stink.

Don 4107

[Nick Badame Refrig/ACC]

Update....

The smell came back within a couple weeks. I then took the anode out as Dr Dave said and it was loaded with so much scum

that it wouldn't come out of the hole. After some prying, I removed it and flushed out the tank 6 times then replaced the anode.

The electric H2O heater has been in operation since sept 05' and almost 3 years it had a really big build up...Hummm...

What causes it to have so much build-up in 3 years?

I have the submicronic filtration system before the hot water tank and I'm puzzeled... I don't winterize the bus, I leave the heat on in the winter.

Nick-

[Sean]

Nick,

I'm amused to read here the various theories and explanations for the smell you are experiencing.  It's quite simple, really, and I would have weighed in here sooner, except I've been tied up for the past few weeks on a Red Cross operation (Hurricane Dolly), with no time to follow the boards.

The "rotten egg" smell is familiar to many with well water in certain parts of the country.  It is caused by a natural phenomenon involving trace amounts of sulfur compounds in the water supply, combined with a specific genus of anaerobic sulfur-eating bacteria that converts the sulfur compounds into hydrogen sulfide gas (either in your tanks, or while the water is still in the well).  Hydrogen sulfide gas is what gives rotten eggs their distinctive smell.

For what it's worth, neither the trace sulfur compounds nor the bacteria (nor the hydrogen sulfide, for that matter) is harmful -- the water is safe to consume.

While you may have neither of these in your own domestic water supply at home, if you have ever filled your tanks from a supply that contains these items (or one supply with each part), you will eventually have the problem.  The bacteria multiply in warm temperatures, and heat also drives dissolved hydrogen sulfide out of solution, which is why the hot water smells, while the cold water does not.  The zinc anode is not directly related to this problem; we have had the rotten egg smell problem many times over four years, and we have no zinc anode in our water system at all.  However, depending on what trace sulfur compounds are in the water, the presence of a zinc anode may facilitate ion exchange with the sulfur molecules that will make them more readily available to the bacteria, thus accelerating the production of the gas.

The cure is to either remove the sulfur or kill the bacteria, or both.

Completely flushing the fresh water tanks as well as the water heater with a supply of known sulfur-free water will remove the sulfur.  "Shock" treating the tanks and the water heater with a bleach solution will kill the bacteria.  When we experience the problem (a result of taking on water from myriad "unknown" supplies all over the country), we do both.

Note that shock-treating just the fresh tank without also treating the water heater will not be completely effective.  Also, leave the bleach solution in the tanks for a good two to four hours.  If you can drive around some to slosh the solution up to the tops of the tanks, so much the better.  The idea here is to kill off everything in the tank -- a good idea anyway, since mildew, mold, and whatever else might be growing on the damp but not submerged walls and tops of the tanks.

For shock treatment, I recommend about one full cup of sodium hypochlorite solution (plain, unscented household bleach) for every 15 gallons of tank capacity.  Run the solution through the hot water tank until a strong scent of chlorine is noticeable coming from the open taps.  Run solution through every tap and fixture, both hot and cold, until the smell is noticeable.

Be certain to drain the entire system and flush with plenty of clear water when done shocking, then re-fill with fresh water.  Your smell problems should be cured for good -- right up until you take on another load of well water with entrained hydrogen sulfide.

Incidentally, the build-up of chemicals on your zinc anode is normal -- the anode is sacrificial; that's what it is supposed to do.  In highly mineral-laden water (common for domestic supplies, especially well water), as the zinc plates out into solution, ions of various other minerals will take its place, albeit with more entrained gas bubbles and the like. making a sort of "crust" on the anode.  Just replace it (as you did) -- that's why it's there.

HTH,

-Sean
http://ourodyssey.blogspot.com

[Nick Badame Refrig/ACC]

Hi Sean,

Thanks for the details of the process!  I'm still a little puzzeled as to why this gets through my Everpure commercial filtration system.

It's submicronic down to  -1/2 micron. I guess the bacteria is smaller then that.

I will do the Bleach treatment tomorrow.

Thanks Again!
Nick-

[Sean]

... I'm still a little puzzeled as to why this gets through my Everpure commercial filtration system.

It's submicronic down to  -1/2 micron. I guess the bacteria is smaller then that.

Nick -- I don't think the bacteria in question can make it through 0.5 micron, however, unless your filter has an "absolute" rating, such as a Doulton ceramic, understand that things bigger than 0.5 microns WILL get through the filter.  You will find that a 0.5 micron filter filters perhaps 99.5% of things 0.5 micron and larger, meaning .5% of those things will get through.  Such a filter starts to approach 100% effectiveness at an order of magnitude larger, so 5.0 micron particles are almost certainly blocked.

That said, hydrogen sulfide will pass a 0.5 micron filter without any problem.  So if the bacteria are making the gas upstream of your filter, you'll still have a problem.

Try the shock treatment and tank flushing and see how it goes.  If that does not work, you might check your water source to see if there is any entrained hydrogen sulfide gas.

-Sean
http://ourodyssey.blogspot.com

[Sean]

Nick, et. al.,

Here's a good web site about this.  And I need to correct myself -- it is a magnesium anode, not zinc.
http://www.water-research.net/sulfate.htm

Also, this Google search will turn up several more sites on the topic:
http://www.google.com/search?q=bacteria+well+hydrogen+sulfide

-Sean
http://ourodyssey.blogspot.com

[Christyhicks]

Sorry Nick, just tuned in and read about your problem.  We've had to go in and replace the standard annode rods with Aluminum ones to solve "rotten egg" issues.  I don't care if the water is safe to use, it's very upsetting to anyone having the problem.  Actually, it shows up in the hot water, because when you heat the water, the "bubbles" release the sulphur smell.  You might check with the manufacturer of your water heater to see if they have suggestions or a different rod to use.  Replacing your annode rog regularly will protect your water heater tank for the long term.  Turning the temperature up to the maximum could help too, but since you have little ones, that may not be a good idea in your case.

I would disagree that R/O water would "etch" anything.  It is true that overly soft water can "seek a balance" and cause problems, but an r/o unit is simply a REALLY good filter.  The water does tase "flat" out of an r/o membrance, so usually, the last filter in line is a carbon filter to add taste back into the water.  Your body actually likes water with some minerals in it.  It would be wasteful to attempt to use r/o water for every fill anyway, as more water is usually rejected than saved on the average r/o unit. 

Usually when we shock our private water system, we turn off our r/o units, dump bleach into the water supply, run every single water tape, including the icemakers, washing machine, dishwasher, showers, etc., until we smell the bleach, then shut down the system and leave it sit overnight.  In the morning, we flush the system completely, and we figure we're good for another year. 

On another vein,  how is business on the East coast?  We've noticed a dramatic slowdown over the last few weeks here, and, since Spring, have been preparing for a slow Fall and Winter, hoping, of course, the whole time that we'd be wrong, ha ha.  Looks like Larry may get a big pole barn this Winter in which to store all of his various tractors, backhoes, and other beamouths he has scattered around in the field here.  I wonder how good these plumbers/hvac techs are at building pole barns!   Christy Hicks

[white-eagle]

once they've built yours, send them our way.  the satellite internet business has tanked for tripods

we just checked into heated storage for a year of cold weather with in/out priviledges and work space - $1200.

Nick, we got to a bluegrass show last weekend and the bus had been sitting for a few weeks of hot weather.  we had about 40% full  fresh water and since it was just a weekend show, i thought we were ok.  Fran turned the water on when we got there, then turned to me and asked if it was checked b4 we left.  SMELL!!!!

i told her to run some into the grey tank and we'd drip it out, then run some fresh in with some added bleach.  but after running about a gallon, the smell went away.  only the kitchen sink seemed to have the problem big time, the others just a slight smell which went away.

i had this problem initially on the way home with the bus when we bought it.  Fran would never have showered in that smell and as Sean said the hot water was worse.  i pitched the hw tank, bleached out the fresh tank, and all had been great until last weekend.

[Nick Badame Refrig/ACC]

Hi Christy,

Ha.. Service is up but, equipment is down sharply....

Seems our customers are thinking twice before buying new units and most resorted to repairing. Should make for a good year next year...

On the commercial end, we sold a record # of Ice Machines so the tourists are here but, just spending less.

Tom,
As members stated above, the anode is most likely full of bacteria and you need to check it.

Good Luck
Nick-

[Nick Badame Refrig/ACC]

Nick, et. al.,

Here's a good web site about this.  And I need to correct myself -- it is a magnesium anode, not zinc.
http://www.water-research.net/sulfate.htm

Also, this Google search will turn up several more sites on the topic:
http://www.google.com/search?q=bacteria+well+hydrogen+sulfide

-Sean
http://ourodyssey.blogspot.com

Hi Sean,
Thanks for the links, very informative!
Here is the link to the filtration system in my bus.
http://www.everpure.com/catalog/productview.asp?type=Tab2&sub=cf&ProductID=EV9324-21&category=foodservice&appn=Ice&market=4&brand=Everpure&app=2

Thanks
nick-

[FloridaCliff]

I have never had this problem!

I always treat the fresh water (110 gallon) with 3 cap fulls of chlorine bleach.

I do this even if I add to it on the road.

It must be enough to kill the bacteria....and still smells fresh even after sitting.

We carry bottled water from our well for drinking.

Cliff

[Sean]

Here is the link to the filtration system in my bus.
http://www.everpure.com/catalog/productview.asp?type=Tab2&sub=cf&ProductID=EV9324-21&category=foodservice&appn=Ice&market=4&brand=Everpure&app=2

Nick,

I surfed over to that site.  It took me a while to find the actual specs on the i2000 cartridge, which is really made for ice machine filtration.  Here's the link:
http://www.everpure.com/catalog/productview.asp?type=Tab2&sub=cf&ProductID=EV9612-21&category=foodservice&appn=Cart.%20Precoat&market=4&brand=Everpure&app=11

The spec is 99.9% of particulates over 0.5 micron.  Note that this is not an absolute rating -- some particles larger than 0.5 micron will pass.  The filter is not rated for bacteria, but it is rated for cysts.

I confess that I do not know the size of the sulfur-reducing bacteria.  It is possible that they are smaller than half a micron.  Bacteria range in size from about 0.3 micron to 10 microns; in order for a filter to be rated for bacteria, it must have an absolute rating of 0.2 micron or smaller; such filters would clog very quickly with normal domestic water.

BTW, do not confuse the term "bacteriostatic" with bacteria removal.  Bacteriostatic simply means that the filter media itself will not support growth of bacteria -- it says nothing about whether the filter will pass any bacteria.  Bacteriostatic filter media is important when the filter will sit for a long time with water in it, but no flow, such as a filter in an RV that is used only occasionally.  I note that the Everpure system is bacteriostatic.  This is usually achieved with minute quantities of silver added to the media.

HTH,

-Sean
http://ourodyssey.blogspot.com

[JackConrad]

Would one of those UV water filters kill the sulphur reducing bacteria?   We have a 6 stage RO on our water at home, but we had the option of going with a 7 stage. The 7th stage was the UV light.  Jack

[Sean]

Jack,

I don't know if UV will kill those bacteria (my guess is that it would), but you don't need to worry about them:  Bacteria are too large to pass through an osmotic membrane.  The smallest bacteria are around 0.2 micron, whereas the pores of an osmotic membrane are smaller than .001 micron -- 200 times smaller.  Even viruses are larger than .02 micron, or 20 times too large to pass through an osmotic membrane.

Consider that RO is commonly used to produce drinking water from raw seawater, which is loaded with microorganisms.  Even the sodium and chloride ions in solution can't pass through the membrane, which is why an RO system can desalinate seawater.

-Sean
http://ourodyssey.blogspot.com