When your shower water smells like rotten eggs, it’s more than just unpleasant — it’s your plumbing system telling you something very specific. That strong sulfur smell comes from hydrogen sulfide gas, and while it’s not usually dangerous, it always points to a problem that needs attention.
The good news?
This issue is 100% fixable, and in most cases, the solution is simple once you know where the smell is coming from.
This guide breaks down the causes, how to quickly diagnose your situation, and the steps you can take to get your shower smelling clean again.
Table of Contents
Quick Diagnosis: Where Is the Rotten Egg Smell Coming From?
Before fixing anything, figure out which category you fall into:
1. Only the hot water smells
This almost always means a water heater issue:
Bacteria inside the tank
Sediment buildup
Anode rod reaction
2. Both hot and cold smell
The odor is coming from the water supply:
Well water with sulfur
Contaminated pipes
Water softener issues
3. Only one bathroom smells
The problem isn’t the water — it’s the shower drain:
Biofilm
Sewer gas
Dry or shallow P-trap
This quick test determines 80% of the cause immediately.
If Only With HOT Shower Water Smells Like Rotten Eggs: Water Heater Issues
When only hot shower water smells like rotten eggs, the problem is inside the water heater.
1. Bacteria in the Water Heater (Most Common)
Not dangerous bacteria — just sulfur bacteria reacting with the heater’s magnesium anode rod.
This produces the sulfur smell.
Fixes:
Flush and sanitize the heater
Replace magnesium anode rod with aluminum or powered anode
Temporarily raise temperature (professional recommended)
2. Anode Rod Reaction
Magnesium rods can react with softened or mineral-heavy water and create hydrogen sulfide gas.
Fix:
Swap to aluminum-zinc or powered anode rod (very effective)
3. Sediment Buildup
Sediment “cooks” when the heater turns on, causing metallic or sulfur-like odors.
Fixes:
Full tank flush
Inspect or replace heating elements if electric
If HOT and COLD Shower Water Smells Like Rotten Egg: Water Supply Issues
When the odor appears in every faucet, it’s not the heater — it’s the incoming water.
1. Hydrogen Sulfide in Well Water
Common in homes using well systems.
Fixes:
Shock chlorinate the well
Install whole-home sulfur filters
Maintain well system annually
2. Corroded Pipes
Old galvanized pipe interiors produce odors when water reacts with the metal.
Fixes:
Replace with copper or PEX
Install point-of-entry filtration
3. Water Softener Problems
An unmaintained softener can produce sulfur-like odors, especially if the brine tank is dirty.
Fixes:
Clean brine tank
Replace resin
Reset or service the system
If Only ONE Shower Water Smells Like Rotten Eggs: Drain Problems, Not Water
This is extremely common — many homeowners assume the water smells when it’s actually the drain.
1. Biofilm in the Drain
Hair, soap, and bacteria form a slimy coating inside the drain pipe. When hot water hits it, it releases a sulfur smell.
Fixes:
Remove drain cover
Scrub pipe walls
Use enzyme cleaners weekly
2. Dry or Shallow P-Trap
If the trap dries out, sewer gas escapes — and sewer gas smells like rotten eggs.
Fixes:
Run water for 30 seconds
Inspect trap for leaks
3. Venting Issues
Blocked or improper venting can push sewer gas into the bathroom.
Fixes:
Clear roof vent
Inspect vent piping
Is Rotten Egg Smell Dangerous?
Generally, no, but it should not be ignored because it can point to:
Bacterial presence
Corrosion
Sediment buildup
Sewer gas leaks
Well water contamination
Fixing it improves safety, smell, and water quality.
How to Prevent the Rotten Egg Smell From Coming Back
Water Heater
Flush annually
Replace anode rod every 3–5 years
Maintain water temperature
Drain
Monthly enzyme cleaning
Clean drain covers
Keep traps full
Water Supply
Replace filters regularly
Maintain well systems
Service water softeners
A little maintenance goes a long way.
Key Takeaways
Rotten-egg smell is caused by hydrogen sulfide gas.
Hot water only = water heater issue.
Hot + cold = water supply issue.
One shower only = drain issue.
Water heater anode rod reactions are the #1 cause.
Drain biofilm is commonly mistaken for water odor.
All issues are fixable with proper diagnosis.
A shower water that smells like rotten eggs doesn’t mean your water is unsafe — it means your plumbing needs attention. Once you identify whether the smell is coming from the water heater, the water supply, or the drain, the fix becomes simple.
Most homeowners don’t need new equipment. They just need the right diagnosis and the right repair.
If your shower water smells like rotten eggs and you want it fixed correctly, Oasis Plumbing can handle the diagnosis, solve the root cause, and make sure the smell doesn’t return.
Call (305) 703-8220 and get clean, fresh water you can trust again.
When water doesn’t move, neither does your day — so if it’s clogged, broken, or smelly, call Oasis Plumbing right away.
Frequently Asked Questions
Why does my shower smell like rotten eggs only when hot water is running?
Your water heater is producing hydrogen sulfide gas due to bacteria, sediment, or the anode rod.
Is sulfur-smelling water safe to shower in?
Yes, but the smell should still be addressed.
Will flushing my water heater remove the smell?
Sometimes — but replacing the anode rod is often the permanent fix.
Why does only one bathroom smell?
Because the drain is the issue, not the water.
Can a water softener cause rotten-egg smells?
Yes — improper maintenance can trigger sulfur odors.
