Sulfur smell in DHW

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Medman

Feeling the Heat
Jul 8, 2008
460
Sault Ste. Marie, Ontario
Relatives of mine have been having this problem. Well water looks and tastes fine, but once the water sits in the DHW tank for a while it comes out smelling like sulfur (rotten eggs). They have been considering a tankless water heater to rectify this problem, but it is a costly solution and they want to make sure there is value in it. Local plumbers are not really in favor of tankless, but I think that is just lack of experience on their part.

I know we have some professionals here on the forum - opinions?
 
Their well water has been tested for minerals and dissolved solids, iron, etc. They have a softener and a polisher tank now, but the testing agency (Culligan) says they don't really need them - they got sold on their current system by a different water treatment company, which has since gone out of business. The only issue seems to be dissolved sulfur, which comes out of solution when the water sits in the DHW tank. If you run cold there is no issue with odor; only the hot has the smell.
 
Sulfur stink is often from iron bacteria. They take up residence in the water heater where they thrive on the high temps. Before the softener installation they likely got this funk growing in the tank. No chlorine in well water to kill bugs. Most homes with wells and no softener will have stinky hot water on old water heaters.
 
Highbeam said:
Sulfur stink is often from iron bacteria. They take up residence in the water heater where they thrive on the high temps. Before the softener installation they likely got this funk growing in the tank. No chlorine in well water to kill bugs. Most homes with wells and no softener will have stinky hot water on old water heaters.
is there a critical temp the water heater can be run for so long to kill the funk?
 
Do they put chlorine in the well once in a while which is a good idea, I have a shallow well and never get the smell and have had water heaters for 20 years or so.
 
You can try replacing the magnesium anode rod(s) with aluminum. That's worked for me every time I've run into this problem.
 
Whenever my tap water starts smelling like sulfur I know its time to replace the house water filter.
 
I removed my water softener when it died, and didn't replace it. I also replaced the water heater, as it was a thousand years old. We have the sulfur smell on one faucet only; the cold water in the main bathroom. I shut off the water and drained that line through a sink in the basement, then filled the line with bleach and let it sit. It worked for quite a while, but the smell is coming back slowly. I may have to do it again. My wife doesn't like the idea of putting bleach in the well, but I'm going to have to do it anyway.

We don't know why it's only that one faucet, as it's used a lot.
 
Follow the feed lines back and see where that faucet branches off. In my house, one of the outdoor taps runs off the main feed before the water filter canister. Its possible that this one faucet is getting its water feed from an unfiltered or unconditioned source and the smell is coming right out of the well, the other taps in the house are getting the smell filtered out in some way...maybe by the house filter or simply distance, dunno.
 
Lucky Phil said:
I removed my water softener when it died, and didn't replace it. I also replaced the water heater, as it was a thousand years old. We have the sulfur smell on one faucet only; the cold water in the main bathroom. I shut off the water and drained that line through a sink in the basement, then filled the line with bleach and let it sit. It worked for quite a while, but the smell is coming back slowly. I may have to do it again. My wife doesn't like the idea of putting bleach in the well, but I'm going to have to do it anyway.

We don't know why it's only that one faucet, as it's used a lot.
Bleach in the well is a good thing once in a while as it helps kill bacteria and you should be doing it on a regular basis.
 
Thanks for the replies. Yes, bleach is used in the well every two years. I will have them check the anode in the tank and possibly replace it with aluminum for now.
Great information!
 
oldspark said:
Lucky Phil said:
I removed my water softener when it died, and didn't replace it. I also replaced the water heater, as it was a thousand years old. We have the sulfur smell on one faucet only; the cold water in the main bathroom. I shut off the water and drained that line through a sink in the basement, then filled the line with bleach and let it sit. It worked for quite a while, but the smell is coming back slowly. I may have to do it again. My wife doesn't like the idea of putting bleach in the well, but I'm going to have to do it anyway.

We don't know why it's only that one faucet, as it's used a lot.
Bleach in the well is a good thing once in a while as it helps kill bacteria and you should be doing it on a regular basis.

I've never heard this before. How much bleach and how do I apply it? Just pop the well cap off and dump it in? My well has been in daily use for nearly 8 years now and I've never done a thing to it except filter the water on its way in.
 
I did it last year; just dumped a gallon of bleach in, circulated through the house, then ran to the ground, as per instructions on the internet. This year, I found a different site that said I should mix 1/2 gallon in a 5 gallon pail of water, dump it in, then do the recirc thing. No water filters or softeners in the house. I do notice a light brown by the drains, so I guess I should put in a filter. Not sure what kind or how large, though.
 
I had this exact problem with my well water. Our solution was a GE whole house filter that can be picked up at any big box store. We grabbed the largest unit (I think 30,000 gallon) and installed it upstream of our softener. Using a charcoal filter (which I also buy at Home Depot) all ordors have disspaeared from my water. I can, however, tell when it's time to change the fitler because I do get the wrotten egg smell back for a few days. I've been very pleased with my setup.
 
Lucky Phil said:
Isn't working for me. Is there a dot in the wrong place?
I dont get it the whole thing is supposed to be a clickable and it will not do it. If I copy and paste the whole line in the address line on my computer it will work.
 
Years ago I worked on a farm that used migrant workers. We used a Chlorinator to keep the water system safe for them. We checked the chlorine level daily. It was a simple pump from grainger that injected chlorine from a seperate 50 gal tank into the water stream enery time the well pump came on. I think that is a very common set up to keep water safe from bacteria in a somewhat public system. I dont see why it coud'nt be used on a typical household system when there is a concern of bacteria in the water, although I am not so sure it would eliminate the sulfur smell though.
 
We have this problem off and on due to iron/sulfur-reducing bacteria, which themselves are harmless but form a nasty sludge in the toilet tanks and water heater. Shocking the well and the water system generally takes care of it for a while plus reduces the iron levels in the well. I dump 1-2 gallons of bleach directly in the well, run the water through a hose back into the well until the water coming out smells like bleach, then run all the faucets and toilets and empty the hot water to fill the system with bleach. Then let sit for 12-24 hours before running a hose to clear the system. Do not run bleach through any charcoal filters; it will use them up quickly.
 
Turn off the feed to the hot water tank & drain down an inch or two.
Open the plug on the top of the tank & pour in one pint of Hydrogen Peroxide.
It'll kill the bacteria & eliminate the smell.
I do it about every two months.
I had half a mind to jerry-rig a small feeder to allow a slow drip of the peroxide into the tank,
but I never got around to it.
Good Luck!
 
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