Why Does My Water Smell Like Sulfur (Rotten Eggs)? How to Tell Where It's Coming From

A rotten-egg smell in your water is almost always hydrogen sulfide gas. The fastest way to find where it comes from is to ask where and when you smell it. The answer usually points to the water heater, a single drain, water that sat unused, or the water supply itself, which is common with well water.

Why Does My Water Smell Like Sulfur? Run This 3-Step Test

• •Smell the cold water at a few taps. Fill a clean glass and smell it away from the drain.
• •Smell the hot water the same way.
• •Check whether the smell is at every tap or only one.

Only the Hot Water Smells: The Water Heater

If cold water is clean and hot water smells, look at the water heater. Sulfate-reducing bacteria can grow in the warm tank and produce hydrogen sulfide, and the magnesium anode rod that protects the tank can feed the reaction. A plumber can flush the tank, check the anode, and advise on options.

Only One Faucet Smells: The Drain

If the glass of water smells fine but the sink smells when you run it, the source is usually bacterial buildup in the drain or trap, not the water. Cleaning the drain often solves it.

It Smells After You Return From a Trip

Water that sits in pipes and the heater for days can develop a smell. Run the taps for a few minutes, hot and cold. If the smell clears and stays away, you are fine. If it returns each time, go back to the hot versus cold test.

Hot and Cold Smell at Every Tap: The Water Supply

If both hot and cold water smell throughout the house, the source is the water coming in. On a private well, hydrogen sulfide is common in groundwater and can come from sulfur bacteria. On city water, it is less common, and you should call your utility to report it.

How Sulfur in Well Water Is Treated

For sulfur and iron in well water, RainSoft of the Wiregrass installs the EC4 OxyTech, a chemical-free filtration system designed to remove iron, sulfur, and manganese. Homes that also have hard water can pair it with an EC5 water conditioner. We start with a free in-home test so the system matches what is actually in your water.