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sulfur smell in water

rm Member Posts: 2
I have a sulfur smell coming from my domestic hot water. We have been trying to sell the house which has been vacant since January. During that time, the water heater was turned down to 90 F. Last week I turned it back up to 125 F. Yesterday I was doing some final cleaning and noticed the smelly water. I know the smell is from the anode (typically magnesium, right?). I ran out all the hot water into the tub, which helped. There was a gray residue in the water, which I'm assuming was the decaying anode remnants.

My question is, is the anode necessarily bad, or is it just that it has been building up in the tank for the last 6 months? The water heater is only a little over a year old, but I have no idea how long the rods are supposed to last. So, does the anode <i>have</i> to be replaced, or do I just need to flush the system? Or should I do both (I guess it wouldn't hurt, right)? Other than just running the water, is there anything else I can do to clean out the system?


  • Dale
    Dale Member Posts: 1,317

    Are you on a well? If so the well may need to be shocked with clorine. If not flush out the heater and turn it up as high as it will go and keep flushing. You could pull the anode rod but the higher temp and flushing should help it.
  • rm
    rm Member Posts: 2
    not well

    Nope, I'm on city water. I guess I'll keep flushing and see if it improves.
  • Geno_9
    Geno_9 Member Posts: 4
    Pull it

    Get a 1/2" or 3/4" socket set with a breaker bar, drain the tank, check the anode{s} and probably replace it. You may have to change the tank. The reason I say that is because you said you were selling the house. Buyers are funny about stuff like that and it might be easier just to be done with it. You know your situation, it's your call.
  • Bob_19
    Bob_19 Member Posts: 94
    You Could

    have bacteria in the tank. This will happen alot when a tank is turned down for a period of time then raised and used. The smell is probably hydrogen sulfide.
    Now this is not to say that the anode rod is not the culprit, but most likly doubtful with the info you have given.
    You should try to disinfect the tank by adding chlorine in small amounts ( be sure tank is off ) then flushing every fixture from the highest to the lowest in that order ending with a tank flush.
    That should remove the pesty little critters.
  • doug_10
    doug_10 Member Posts: 102
    My $0.02


    When you mentioned the "gray" matter in the bath water, was it settled to the bottom easily or did it stay mostly suspended in the water?

    If it settled it may be the Mg remnants as you stated...if it's a lighter gray - in color and density - then it's "bugs".

    If you're not sure, do both the disinfection and the anode replacement. For disinfection, use about 1 oz. of bleach with NO additives (like surfactants)...just Sodium Hypochlorite...for every 10 gallons of water in the tank.

    Dilute this with some tap water and put it in the
    tank...let it sit for at least five minutes and up to 30 minutes, then flush it through the piping as described earlier as well.

    When you flush it through, if you have aerators you should smell the residual...as soon as you smell it shut off that tap and move on. When all taps are done, start at the beginning tap and flush the whole system. This gives a short detention time in the pipes and fixtures. Don't forget to turn the HWH back on (high setting) when done.

    I'm thinking it's probably the bacteria due to the temperature setting and the long period of non-use (the Cl2 residual was long gone), but it's just a guess.

    Good luck. Take Care, PJO
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