The short answer
Check the Drains First
The most common cause of a rotten egg smell in a basement is bacteria growing in the drain pipes. Over time, organic matter like soap scum and hair can build up, and bacteria break it down, releasing hydrogen sulfide gas. This smell often comes up through the sink or floor drain, especially if the drain hasn't been used in a while.
Run water down every basement drain for a minute or two to see if the smell fades. If it does, the issue is likely just stagnant water in the trap. Pouring a cup of baking soda down the drain followed by white vinegar can help neutralize odors. If the smell persists, you may need a plumber to clean the pipes.
Inspect the Water Heater
Another frequent culprit is the sacrificial anode rod inside your water heater. This rod is designed to corrode to protect the tank, but over time it can produce hydrogen sulfide gas, especially if the water has high sulfate content or certain bacteria. The smell then travels through the hot water pipes and into your basement.
If the smell is stronger when you run hot water, the anode rod is a likely cause. A plumber can inspect the rod and replace it with a different type, such as an aluminum or powered anode, which may reduce the odor. Flushing the water heater can also help remove sediment that contributes to the problem.
- Smell stronger with hot water? Suspect the anode rod.
- Run cold water only to compare the odor.
- Flush the water heater to remove sediment.
- Have a plumber check the rod type.
- Consider a powered anode rod as an alternative.
Look for Sewage Leaks
A more serious cause is a sewage leak or backup in the basement floor drain or waste pipes. If sewage is seeping into the concrete or under the floor, the smell can be strong and persistent. This situation requires immediate attention because it can pose health risks from bacteria and mold.
Look for damp spots, stains, or pooling water near drains or along walls. If you suspect a sewage leak, stop using the basement and contact a plumber or a water damage professional to assess the situation. They can locate the leak and determine if cleanup and drying are needed.
Rule Out Gas Leaks
Natural gas itself is odorless, but utility companies add a chemical called mercaptan to give it a distinct rotten egg smell. If the smell is very strong and you notice it near gas appliances like a furnace, water heater, or stove, you may have a gas leak. This is an emergency situation.
Leave the basement immediately and go outside. Do not flip any light switches or use the phone until you are away from the area. Call your gas company or emergency services from a safe location. Only a qualified professional should investigate or repair a gas leak.
When to Call the Pros
If you cannot find the source or the smell persists after basic troubleshooting, it is time to call local water damage pros. They can use moisture mapping and leak detection to find hidden water or sewage issues. They can also assess whether structural drying and dehumidification are needed to prevent mold growth.
In some cases, the smell may come from organic material that got wet, like drywall or flooring. The pros can help identify water damage and recommend removal or repair. If you live in South Jordan, keep your shutoff valve location written down, but always rely on professionals for complex issues.
Policies vary, and your insurer decides what is covered. If you suspect water damage, check your policy to see what might be included.
- Persistent smell after cleaning drains? Call the pros.
- Suspected sewage leak? Get a professional assessment.
- Water damage in drywall or flooring? Consider removal and drying.
- Use leak detection services to find hidden sources.
- Moisture mapping can reveal damp areas that cause odors.
Talk to someone now
Call (801) 845-3042 any time, day or night, and describe what happened.
Call Now (801) 845-3042Frequently asked questions
Can a rotten egg smell be harmful to my health?
Yes, in high concentrations, hydrogen sulfide can cause headaches, nausea, or breathing issues. Sewage leaks also carry bacteria and mold risks. If you feel unwell, see a doctor. For any gas leak, leave the area immediately and call emergency services.
Will the smell go away on its own?
Sometimes, if it is just a dry drain, running water will flush it out. But if the source is a water heater anode or a sewage leak, the smell will persist and may worsen. You need to address the root cause, not just mask the odor.
Should I use bleach to get rid of the smell?
Bleach can kill bacteria in drains, but it may not solve the problem if the smell comes from the water heater or sewage. Also, bleach can react with other chemicals and create fumes. Try baking soda and vinegar first, then call a plumber if the smell remains.