A rotten egg smell in your water is almost always hydrogen sulfide gas, and it’s generally not harmful to your health, though it smells and tastes awful. If it only shows up in hot water, the water heater is the likely culprit. If it’s in both hot and cold, the source is probably your water supply. One important exception is if you smell it near a gas appliance or without running any water, because that could be a natural gas leak, and that needs a different response. Here’s how to tell which one you’re dealing with.
First, Rule Out a Gas Leak
Natural gas is naturally odorless, and utilities add a sulfur smell on purpose so you can detect a leak. That means a “rotten egg” smell in your home might not be the water at all.
If you smell it near your furnace, stove, or water heater, or you notice it when no water is running, get everyone out of the house and call your gas provider or 911 from outside. Don’t flip light switches or use your phone inside. If the smell only shows up when you run a faucet, keep reading.
What Causes the Smell in Your Water
According to the U.S. Geological Survey, hydrogen sulfide gas develops when water comes into contact with organic matter or certain minerals as groundwater moves through the ground. The USGS says water with this odor is generally not harmful to health, although the smell and taste are objectionable.
In a home, the smell usually comes from one of a few places.
Your water heater. Purdue Extension explains that heated water releases hydrogen sulfide gas faster than cold water, and that the magnesium anode rod inside many tanks can contribute. As the rod gives up small amounts of magnesium to protect the tank from corrosion, hydrogen is released, and it can combine with sulfur in the water to form hydrogen sulfide. That’s why many homeowners notice the smell only when they run hot water.
Your water supply. If both hot and cold water smell, the sulfur is likely already in the water coming into your home. This is more common for homes on private wells, since groundwater can pick up sulfur compounds on its way to you.
A drain, not the water. Sometimes the smell is coming from the sink itself. A gurgling sound or a smell that’s stronger when you lean over the drain, but not when you smell a glass of water, points to the drain or trap. Pouring water down a rarely used drain can refill a dry trap and stop the smell.
Quick Way to Narrow It Down
Try this simple test:
- Run the cold water in a sink for 30 seconds, then fill a glass and smell it away from the drain.
- Do the same with the hot water.
- Carry each glass into another room to make sure you’re smelling the water and not the drain.
If only the hot water smells, the water heater is the likely cause. If both smell, look at your water source. If neither smells, it’s the drain.
How to Fix It
If it’s only the hot water. A plumber can flush the tank and check the anode rod. In some cases, swapping the anode rod for a different type can reduce the smell, and a thorough flush clears out sediment that gives odor causing bacteria a place to live. If the tank is old and heavily corroded, replacement may be the better long term answer.
If it’s both hot and cold. The next step is to find out exactly what’s in your water. The USGS recommends having your water tested by a state certified laboratory, and says your local health department or county Extension office can point you in the right direction. If you’re on a private well, testing is especially worthwhile.
If testing confirms sulfur in the water. A whole home filtration system can reduce it. Purdue Extension lists several treatment options for hydrogen sulfide, including activated carbon filters, aeration, and iron removal filters, and the right one depends on how much sulfur is in your water. That’s a conversation for a professional, not a one size fits all fix.
Michigan Homes and Water Quality
Water quality varies a lot across Michigan, from city water in towns to private wells out in the country. Hard water is common across the state, and it can create its own problems with scale, low flow, and appliance wear. Smells, tastes, and mineral buildup are often connected, which is why we like to look at the whole picture instead of treating just one symptom.
When to Call a Plumber
Call us if any of these apply:
- The smell is only in the hot water and doesn’t go away after a day or two
- You’ve tested the water and want help choosing a treatment system
- The smell comes with discolored water, a metallic taste, or a drop in water pressure
- Your water heater is more than 10 years old and starting to show other problems
- You’re not sure whether the smell is coming from the water, the drains, or a gas appliance
How Aspen Plumbing Services Can Help
At Aspen Plumbing Services, we’ve been serving Jackson County since 1981. We service and replace water heaters, and we install water filtration and water softening systems for homes across Michigan. We’ll help you figure out where the smell is actually coming from before recommending anything, so you’re not paying for a fix you don’t need.
Give us a call at (517) 750-9913. We’re available 24/7 for emergencies, and we serve Jackson County plus Ingham, Eaton, Calhoun, Hillsdale, Lenawee, and Washtenaw counties. We also offer free estimates on new installations.
Frequently Asked Questions
Is rotten egg smelling water safe to drink?
In most cases, it’s not harmful to your health. The U.S. Geological Survey says water with a hydrogen sulfide odor is generally not harmful, even though the smell and taste are unpleasant. If you’re concerned, or you’re on a private well, we recommend having the water tested by a state certified lab.
Why does only my hot water smell like rotten eggs?
That usually points to your water heater. Heated water releases hydrogen sulfide gas faster than cold water, and the anode rod inside many tanks can contribute to the smell. A flush and an anode rod check often help, and we can handle both.
Could the rotten egg smell be a gas leak?
It can be. Utilities add a sulfur smell to natural gas so leaks are easy to notice. If you smell it near a gas appliance, or when no water is running, leave the house right away and call your gas provider or 911 from outside. Don’t use light switches or your phone inside until you’re clear.
How do I get rid of the smell in my water heater?
Start by having the tank flushed and the anode rod checked. Sediment gives odor causing bacteria a place to live, and cleaning it out can make a big difference. In some cases, swapping the anode rod helps. If the tank is very old or badly corroded, replacement may be the better option.
Can a water filter remove the rotten egg smell?
Often, yes. Activated carbon filters, aeration systems, and iron removal filters are all used to treat hydrogen sulfide. The right choice depends on how much sulfur is in your water, so we recommend testing first and then picking a system that matches the result.
Why does my water smell worse after being away?
Water that sits in pipes or in the water heater for a few days can build up odors. Running the hot and cold taps for a few minutes after a trip often clears it. If the smell comes back every time, the water heater is a good place to look.
Do you offer free estimates for water filtration or a new water heater?
Yes, we offer free estimates on new installations. We’ll look at your setup, find the cause of the smell, and explain your options before any work begins. Financing is available if you’d like to spread out the cost.
Aspen Plumbing Services proudly serves the greater Jackson, Michigan area and the surrounding areas, including Spring Arbor, Marshall, & Onsted. Questions about pour water quality services? Contact our team today.
