Why Does My Hot Water Smell Like Rotten Eggs?
If you’ve turned on your shower or sink lately and caught a strong sulfur or rotten egg smell, you’re not alone. We get this question from homeowners all the time, especially those with well water. The odor might seem minor at first, but it often points to a fixable issue that shouldn’t be ignored.
As home inspectors, we’ve seen how plumbing problems can go from annoying to costly if left unchecked. Let’s walk through what’s causing that smell, how serious it really is, and what you can do about it.
What’s Causing the Rotten Egg Smell in Hot Water?
That strong, unpleasant smell comes from a gas called hydrogen sulfide. It’s often the result of bacteria reacting with minerals in your water supply.
Here are the most common culprits:
Bacteria in the water heater: Warm water creates a perfect environment for sulfur bacteria to grow. These bacteria feed on sulfates and produce hydrogen sulfide as a byproduct.
Well water with high sulfur content: If your home runs on well water, you may have naturally high sulfur or sulfate levels. This isn’t dangerous in most cases, but it does affect smell and taste.
Corroded anode rod in your water heater: Anode rods protect your water heater from rust, but over time they can react with bacteria and create that rotten egg odor, especially if the rod is magnesium-based.
The odor usually shows up only in hot water, which helps narrow things down. If your cold water smells fine but your hot water stinks, it’s almost always tied to the water heater or bacterial buildup in the system.
(Source: EPA.gov)
Is It Dangerous or Just Annoying?
In most homes, the smell itself isn’t harmful, but that doesn’t mean you should ignore it.
Hydrogen sulfide isn’t toxic at the low levels that cause odor, but it can corrode pipes, stain fixtures, and create buildup that slows water flow. If you’re noticing slime in your drains or your water pressure has dropped, there could be more going on behind the scenes.
According to the EPA, hydrogen sulfide levels over 0.5 mg/L can lead to a noticeable smell and long-term damage to plumbing systems. That level also suggests bacteria may be present in your water supply, especially if you have a private well.
If anyone in your household has asthma or a sensitivity to strong smells, this issue can cause headaches, nausea, or respiratory irritation. While not dangerous to most, it’s still worth taking seriously.
How Inspectors can help
Before you replace your water heater or install expensive filters, it’s important to identify the real source of the smell. Here’s how a professional inspector will typically approach:
Check if it’s only the hot water: If cold water smells fine, it’s probably a water heater issue.
Test multiple faucets: If the odor is isolated to one bathroom or sink, you might be dealing with localized plumbing buildup instead of a whole-house issue.
Inspect the water heater: We look for signs of bacterial growth, corrosion, and sediment. We also check the condition of the anode rod and tank interior.
Recommend water testing: Especially if you’re on a well system, a full water quality test can confirm if sulfur, bacteria, or other minerals are causing the problem.
Many homeowners try quick fixes, like using scented soaps or running the water longer. But those only mask the smell.
How to Get Rid of the Smell
If you’re a DIY-minded homeowner, there are a few steps you can try before calling in the pros:
Flush your water heater: Sediment buildup at the bottom of the tank often contributes to the smell. Flushing it once or twice a year can help reduce bacteria.
Sanitize the tank: Many homeowners use a hydrogen peroxide flush to clean out bacteria safely.
Replace the anode rod: Switching from a magnesium rod to an aluminum or zinc alloy rod can help eliminate the sulfur reaction.
If those steps don’t work or the smell returns quickly, it may be time for a more permanent solution, like installing a filtration or aeration system.
They're designed to remove hydrogen sulfide and other minerals from well water. Basic systems start around $300, while advanced models can run closer to $1,200 with installation.
Of course, it's always a good call to hire a professional for help. If bacteria have spread beyond the tank into your plumbing, you’ll need a professional treatment plan to fully disinfect the system.
Simple routine maintenance
Maintenance to Avoid Future Issues
The best way to prevent this problem from coming back is to stay on top of regular maintenance! Here’s what you can do:
Flush your water heater every 6 to 12 months
Test well water annually for pH, sulfur, bacteria, and mineral content
Inspect plumbing for signs of corrosion or buildup during your home maintenance checkups
Many homes that experience this issue tested their water in years (if ever).
When to Call a Professional
You don’t need to panic over a bad smell in your hot water, but there are times when a professional inspection is the best move:
The smell lingers after you flush or disinfect your water heater
Both hot and cold water have a strong odor
You use well water and haven’t had it tested recently
You notice other issues like slime, discolored water, or low pressure
At Taylor Made, we help owners figure out what’s really going on with their home's main systems. Whether the issue is in your heater, your plumbing, or your well, we’ll help you find the source and fix it the right way.
Conclusion
That rotten egg smell in your hot water isn’t just a nuisance—it’s often a sign that your system needs attention. Whether it’s bacteria in your tank, sulfur in your well, or something else hiding in your pipes, the sooner you investigate, the better.
Need help getting to the bottom of it? Our team at Taylor Made is here to help with full inspections and plumbing system evaluations. If something smells off, let’s take a closer look.
