I bought a very old house. The cold water has the sulfur smell, but my hot water doesn't. We have a very new hot water heater. Is this due to the hot water heater's sacrificial anode attracting the bacteria causing this smell?

Also, to get rid of the smell, would it suffice to run hydrogen peroxide through the pipes? Or do I need to replace them?

  • 1
    Any problem in the water heater would be unlikely to affect the cold water. Is this smell present at every cold water faucet location, even outside garden faucets? Are you sure the smell is not coming from the drain system, where you think it's the water but it's the drain near the tap/faucet? May 6, 2017 at 1:47
  • it is happening in all of the indoor faucets. I do have an outdoor spigot that I haven't checked. My neighbor's water has no smell at all though. Also, I should note that it is city water ( not well). The drains are all new (I installed new tub and sink) in my bathroom...
    – statsNoob
    May 6, 2017 at 1:51
  • What part of the world is this located in, approximately? Do the neighbors have similar water smell?
    – wallyk
    May 6, 2017 at 3:53
  • Florida. Neighbors water has no smell.
    – statsNoob
    May 6, 2017 at 8:58
  • @statsnewb Are you on city water or do you have a well , septic system?
    – Ken
    May 6, 2017 at 13:14

3 Answers 3


Being in Florida and on City Water - and only the cold water is affected.

Your water heater is not the culprit.

However, you stated a very important fact and left off another possibility - you are in Florida and many homes in Florida might be equipped with an irrigation system, and if your home is equipped with one, see the following.

Usually, the irrigation system will have a back flow valve (check valve) to prevent back flow from the irrigation system running into your home.

There are also water filtration systems for homes, does your home have a filtration system ?

The other possibility is that you have a cracked pipe running into the house or a tree root has found your inlet water line and broke it a bit. Turn the water off inside the house for a 1/2 day (Take a picture) - go out for a while and when you come back take another picture and see if your water meter budged even a blip.

Your hot water heater is cooking the water - so the smell is not there - but the sulphur is sticking to / burning on the tank heating rods.


The smell is hydrogen sulfide, it is detectable at much less than 1 ppm. It is in your water supply. Usually caused by sulfate reducing bacteria in a well. Because others with the same water don't have it , apparently the bacteria are in your system.


In a system with a well the pressure tank can be the cause of bad smelling water when the bladder fails and the water is in contact with air. The tank may still function as long as it has air in it one way to find out if the bladder has failed is to turn the pump off and turn the water on . when the air pushes all the water out and then some air gets out the tank would have to be repressurized until it can be replaced but this is common in older homes with wells and the water stink is resolved with a new pressure tank if it is not the water itself.

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