A rotten egg smell around your water heater is one of those problems that can be completely harmless or a real emergency, and the smell alone does not tell you which. In many Englewood homes it turns out to be a reaction happening inside the tank, which is annoying but not dangerous. Sometimes, though, it is natural gas. Knowing how to tell the two apart in the first minute matters, and so does knowing when the fix is a simple water heater repair in Englewood rather than something you should leave the house for.
First, Rule Out a Gas Leak
Natural gas has no smell of its own. Utilities add an odorant so leaks can be noticed, and that odorant smells like rotten eggs. That is why this question always starts with safety.
Treat the smell as a possible gas leak if:
- You smell it in the air near the water heater, furnace or boiler, even when no water is running
- The smell is strong, spreading, or getting worse
- You hear hissing near a gas line or appliance connection
- The smell is in several rooms, not just at a faucet
If any of those are true, leave the house right away. Do not flip light switches, use appliances, or start the car in the garage on your way out. Once you are outside and away from the smell, call 911. Do not go back in until the area has been cleared.
After the concern department has made the home safe, our gas line services team can locate the source with electronic leak detection, repair it, and pressure test the line.
The Faucet Test: Is the Smell Coming From Your Hot Water?
If the smell only shows up when you run water, you are most likely dealing with the water, not a gas leak. A quick test narrows it down:
- Run the cold water at a sink and smell it.
- Run the hot water at the same sink and smell it.
If both hot and cold water smell, the issue is more likely in the water supply itself and is worth reporting to your water provider.
Why a Water Heater Can Make Hot Water Smell
The smell comes from hydrogen sulfide gas. According to the Colorado Department of Health, a water heater can provide an ideal environment for converting sulfate in the water into hydrogen sulfide.
The anode rod
Many tank water heaters have an anode rod inside the tank, which helps protect the tank from corrosion. The Colorado Department of Health notes that many water heaters have a magnesium anode, and that this type can contribute to the smell. The Colorado Department of Health notes that a replacement anode, such as an aluminum one, may still protect the tank without contributing to the odor.
A tank that sits unused
Water that sits in the tank unused for a while, such as after a vacation, may smell worse when it is first run. If the smell fades after the water runs for a minute, that points to the tank rather than your plumbing.
Is the water safe?
In most cases, the rotten egg smell does not relate to the sanitary quality of the water. That said, if the smell is new, strong, or comes with a change in color or taste, have it checked rather than assume.
What About a Sewer Smell Near the Water Heater?
There is a third possibility worth knowing. Water heaters are often installed near a basement floor drain, and a drain that is rarely used can be a source of odors too. A sewer smell is easy to confuse with rotten eggs. Pouring water into the floor drain is an easy first check. If the smell goes away, you have likely found the cause. If it comes back, have the drain looked at.
Fixes That Work, and When to Call for Water Heater Repair in Englewood
Once a gas leak is ruled out, these are the usual fixes for sulfur-smelling hot water.
Replacing the anode rod
Swapping the existing anode for a different type is the fix the Colorado Department of Health describes. It is a job for a plumber, since the rod has to come out of a tank that has been in service for years. Removing the anode entirely is not a fix, because the rod is there to protect the tank.
Flushing the tank
Flushing removes sediment that has collected at the bottom of the tank. Follow the manufacturer’s instructions for your heater. If the tank has not been flushed in years, the drain valve may not close properly afterward, so this is a good job to hand to a plumber.
Disinfecting the tank
Some sources recommend raising the water heater temperature to kill odor-causing bacteria. The Colorado Department of Health describes this method but also warns that increasing the water heater temperature can be dangerous because of the scalding risk. This is not something to do on your own.
Replacing the water heater
If the tank is older, shows corrosion, or the smell keeps coming back after an anode swap, replacement may be the better long-term value. Our guide on when it’s time for a water heater replacement in Englewood walks through that decision.
Whichever route makes sense, we inspect the water heater first and give you a clear, upfront price before any work begins. Learn more about our water heater repair and replacement service.
Frequently Asked Questions
Why does only my hot water smell like rotten eggs?
When the cold water smells normal and only the hot water smells, the Colorado Department of Health notes that the problem is likely in the water heater.
Is it dangerous to shower in water that smells like sulfur?
In most cases, the smell is not related to the sanitary quality of the water. If the smell is sudden or strong, or the water also changes color or taste, have it checked.
Can I just remove the anode rod to stop the smell?
No. The anode rod is there to protect the tank from corrosion. Replacing it with a different type is the better fix.
How do I know if it’s a gas leak and not my water?
A gas leak smell is in the air, often near gas appliances, and is there even when no water is running. A water problem shows up at the faucet when the water runs. If you are unsure, leave the house and call Xcel Energy at 800-895-2999 or 911.
How quickly can you come out for water heater repair in Englewood?
We offer same-day service whenever possible and often reach nearby homes within an hour for urgent calls.
Get the Smell Taken Care Of
If your hot water smells like rotten eggs, call A Clear Choice Plumbing & Heating at (720) 938-1554. We are a licensed and insured local team based right here in Englewood, providing water heater repair across Englewood and the Denver metro. You can also request a quote online.
