The short answer
Check for a Gas Leak First
Natural gas has a chemical added to it that smells like rotten eggs. This is the most serious cause, so take it seriously. If you smell it near a gas stove, water heater, or furnace, leave the house and call your gas company from outside. Do not flip light switches or use any electronics.
A small leak can come from a loose fitting or a damaged line. A plumber can test the gas lines and find the source. If you live in Rockwall, keep your shutoff valve location written down so you can turn off the gas safely if needed.
- Smell strongest near the floor? Gas is lighter than air, but it spreads.
- Listen for a hissing sound near gas appliances.
- Check the pilot light on your water heater.
- Look for soot or a yellow flame, which can mean incomplete burning.
Water Heater Problems
A water heater can produce a rotten egg smell when the anode rod reacts with sulfur in the water. This creates hydrogen sulfide gas, which smells like sewage or rotten eggs. The smell often comes from the hot water taps, not the air.
If the smell appears only when you run hot water, the water heater is likely the culprit. A plumber can replace the anode rod or flush the tank. This is a common fix and usually solves the problem.
Sulfur in Well Water
If your home uses well water, sulfur bacteria can produce hydrogen sulfide. This can make both hot and cold water smell. The smell may be stronger in the bathroom or kitchen where water is used most.
A water test can confirm if sulfur is the cause. Treatment options include aeration, filtration, or adding chlorine. A water treatment professional can help you choose the right system for your home.
- Run the water for a few minutes to see if the smell fades.
- Check the water heater temperature; below 120F can encourage bacteria.
- Inspect the well cap for cracks or damage.
- Test the water for sulfur and bacteria.
Drains and Plumbing Buildup
Bacteria in drains can produce a rotten egg smell, especially in kitchen sinks or bathroom drains. Food particles and soap scum create a film where bacteria grow. This is usually a localized smell, not the whole house.
Pouring boiling water down the drain can help, but if the smell persists, the issue may be in the vent pipe or a blocked drain line. A plumber can clean the pipes or replace a section if needed.
When to Call the Pros
If you cannot find the source of the smell, or if it gets stronger, call water damage pros for an inspection. They can check for hidden water damage that might be causing mold or mildew, which can sometimes smell musty, but a rotten egg smell is more often gas or sulfur.
For gas leaks, always start with your gas company. For water heater or plumbing issues, a plumber is the right choice. If you suspect water damage, a water damage inspection can identify moisture problems before they worsen.
Water damage does not wait
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (469) 698-4610Frequently asked questions
Is a rotten egg smell always a gas leak?
Not always. It can also come from a water heater anode rod, sulfur in well water, or bacteria in drains. But you should treat it as a potential gas leak until you know the source. If you smell it and cannot find the cause, leave and call your gas company.
Why does the smell come from the hot water only?
That usually points to the water heater. The anode rod can react with sulfur in the water, creating hydrogen sulfide gas. Running hot water releases the gas. A plumber can replace the anode rod or flush the tank to fix it.
Can water damage cause a rotten egg smell?
Water damage usually leads to musty or earthy smells, not rotten eggs. But hidden moisture can cause mold, which might mix with other odors. If you suspect water damage, a water damage inspection can help find the source of moisture.