Plumbing tips · October 14, 2026
The rotten egg smell from the hot water
If the hot water smells like rotten eggs and the cold water does not, the smell is almost always being made inside the water heater. It is unpleasant, but it is usually fixable without a new tank.
Hot only, or hot and cold?
Run the cold tap and smell it, then the hot. If only the hot water smells, look at the water heater. If both smell, the cause is more likely in the water coming into the house, which is common on well water and calls for a different fix.
What makes the smell
Most tank water heaters have a metal rod inside called the anode, there to protect the tank from rusting. Bacteria that live in warm, still water can react with it and give off hydrogen sulfide gas, which is the rotten egg smell. A tank that sits unused, or one turned down low, gives them more chance.
The usual fixes
Flushing the tank clears out sediment the bacteria live in. Replacing the anode with a different type, often aluminum-zinc or a powered anode, usually stops the smell for good. Some tanks are also disinfected as part of the job. Removing the anode altogether stops the smell but lets the tank rust, so that is not the answer.
When it is not the water heater
Gas companies add a rotten egg smell to natural gas and propane so a leak can be noticed. If you smell it in the air near the water heater, the stove or anywhere other than at the hot tap, treat it as a gas leak: leave the house and call the gas company from outside.
Questions we get asked
Is it safe to shower in hot water that smells like rotten eggs?
The amount in the water is usually small and more of a nuisance than a danger, but it is a sign the water heater needs attention. Have it looked at rather than living with it.Why did the smell start after we were away?
Water sitting still and warm in the tank while nobody uses it gives the bacteria time to build up. Running the hot water for a while can help for now, but the smell tends to come back until the cause is fixed.Will turning the water heater up get rid of it?
Hotter water can slow the bacteria down, but it also raises the risk of scalding, so it is not a fix to try on your own. Flushing the tank and changing the anode deal with the cause.Plumbing questions we answer
Where we go
Parker, Wise and Tarrant County, out of the shop in Springtown. Springtown, Weatherford, Azle, Boyd, Decatur, Newark, Millsap, Fort Worth and the country in between.
Call 817-487-8866