International Association of Certified Home Inspectors

Water Heaters: What's That Rotten Egg Smell?

Phew! When you turn on the hot water, it might stink. Rotten-egg odor or black water in hot water lines is due to the reaction of sulfates and micro-organisms in the water that create hydrogen sulfide (H₂S). This is a water chemistry condition, rather than a water heater problem. Water heater manufacturers Rheem and Ruud have published a technical bulletin to help you eliminate the odor problem.