American Water Heaters Odor from Sulfate-Reducing Bacteria / Anode Reaction

Hot water has a rotten egg or sulfur smell.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Magnesium anode reacting with sulfur in water, Bacterial growth in tank, Low hot water usage leading to stagnation

Safety: Use caution when handling hot water and chemicals. Follow local codes for disinfection.

1. Shock chlorination: Drain the tank partially and introduce a chlorine solution per manufacturer or plumbing guidelines. Let sit, then flush thoroughly.
2. Replace anode: Consider replacing the magnesium anode with an aluminum/zinc anode rod designed to reduce odor.
3. Increase usage or temperature (temporarily): Temporarily raising water temperature (with caution) can help kill bacteria; then return to safe levels.

Medium 3/5

Anode Rod (Aluminum/Zinc Replacement)

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