This gas doesn’t just appear out of nowhere. It forms when sulfur-loving bacteria feast inside your water heater or pipes. These tiny guys are like microscopic party animals that thrive in warm, dark places.
Their favorite snack is magnesium or aluminum from your sacrificial anode rod. The rod is a metal bar intentionally placed inside your water heater to rust instead of the tank. When bacteria munch on it, they burp out hydrogen sulfide.
So, your water smells funky because of bacterial farts in your heater. If that doesn’t make you smile, nothing will.
The Cold Clue
You might wonder: “Why does only the cold water stink?” Hot water often masks the smell because heat drives off the gas faster. Cold water, however, is like a jail cell for the stench—it traps the gas and delivers it right to your nose.
Check your cold water supply line. If the smell disappears after running the tap for a minute, the bacteria are chilling right inside your faucet’s aerator. That little mesh screen is a perfect bacteria hotel.
Another twist: if your hot water also smells, the problem is almost certainly the water heater itself. If only cold water reeks, the source is likely your well water or old pipes.
Rotten Egg Smell In House
