Why does my hot water smell like rotten eggs?
That rotten-egg smell is hydrogen sulfide in the water. The first thing to pin down: does only the hot water smell, or both hot and cold? Hot only usually points to the water heater. Both hot and cold usually points to the water supply itself, which we see more often on well systems.
First, the question that splits it: hot only, or hot and cold?
This is the most useful thing you can check. Run the cold water at a tap and smell it, then run the hot. If only the hot smells, the water heater is usually involved. If both smell the same, the odor is coming in with your water supply, not from the heater.
When it’s the water heater (hot only)
Inside a tank, the smell tends to show up when water sits for a long time. A heater that gets very little use, or a large tank serving a household that doesn’t draw much hot water, lets water sit long enough for the odor to develop. The water and the components inside the tank, including the anode rod, can interact and contribute. We don’t treat swapping the anode rod as an automatic fix, the right move depends on your usage, your tank, and where your water comes from, so it’s worth diagnosing rather than guessing.
When it’s the water supply (hot and cold)
If both the hot and cold smell, the sulfur is in the water coming into the house. This is most common on well systems, and around here we see it most in Chapin and the more rural parts of the Irmo area. On a well, the water and the heater can interact and make a hot-side smell worse, but the root is the supply.
When to call
If you can’t clear it, or you’re not sure whether it’s the heater or the supply, we’ll diagnose where the smell is actually coming from before recommending anything. Same-day service across the Midlands during business hours.
Quick answers
Smelly hot water? We’ll figure out whether it’s your heater or your water, then tell you straight.