When you turn on your hot water, a foul odour is the last thing you want to find coming from the tap. A bad smell from your hot water heater is a warning that there is a problem inside the unit.
When a hot water heater smells, the odour of rotten eggs probably will be the most noticeable sign. While the odour is not harmful, it will make showering unpleasant and the taste makes drinking the water or cooking with it difficult.
The cause of the smell in a hot water heater is sulphur-reducing bacteria. This bacteria lives in the hot water heater and emits hydrogen sulphide gas, which causes the bad smell. This frequently happens after hot water heaters are turned off or set below 60 degrees Celsius (140 degrees Fahrenheit).
Get rid of the bacteria and smell by raising the hot water heater's temperature above 60 degrees C (140 degrees Fahrenheit) for several hours, then flush the water from the tank. The bacteria might return unless a zinc rod is installed inside the hot water heater. Before making modifications, ask a plumbing professional because this could void a warranty on the unit.