Why does my water heater smell like sulfur?

Sulfur smell from your water heater is almost always caused by bacteria in the tank reacting with the anode rod, creating hydrogen sulfide gas that smells like rotten eggs. This is more common with well water but can happen with city water too.

The anode rod in your water heater is designed to prevent tank corrosion by attracting minerals and sediment. However, certain bacteria can feed on this rod and produce hydrogen sulfide gas. This is especially common if your water heater has been sitting unused for a while, if you have well water with high sulfur content, or if your tank temperature is set too low (below 140°F).

In Ottawa's water system, this issue occasionally occurs in areas with older infrastructure or homes with well water in rural parts of the service area. The smell is typically most noticeable when you first turn on hot water after it hasn't been used for several hours.

Safety-wise, hydrogen sulfide gas isn't dangerous at the low levels produced by water heaters, but it's unpleasant and indicates bacteria growth in your tank. You can try flushing the tank and temporarily raising the temperature to 160°F for a few hours to kill bacteria, then lowering it back to 120-140°F. However, if the smell persists, the anode rod may need replacement or you might need a different type of anode rod (aluminum instead of magnesium).

This repair typically requires draining the tank and specialized tools to remove the anode rod, which can be challenging for homeowners. A licensed plumber can diagnose the exact cause, replace the anode rod if needed, and ensure your water heater is operating safely. In Ottawa, anode rod replacement typically runs $200-400 depending on accessibility.

For a proper diagnosis of your water heater's sulfur smell, Ottawa Pro Plumbing offers free consultations to determine the best solution for your specific situation.