Water Heater Repair - KCs Plumbing, Heating and Drains

Water Heater Smells Like Rotten Eggs: What's Causing It

If the smell only shows up in your hot water, not the cold, the water heater is almost always the source, not the city supply. The good news is that a rotten-egg smell is rarely dangerous on its own, and it's usually fixable without replacing the tank. If your water heater is still under eight years old, then chances are good a routine water heater repair will be enough to get it up and running again.

The Most Common Cause: Bacteria and the Anode Rod

Most water heaters have a sacrificial anode rod inside the tank. It's designed to corrode instead of the tank itself, which is what makes the tank last as long as it does. In some water conditions, naturally occurring sulfate-reducing bacteria in the tank react with the rod and produce hydrogen sulfide gas, the same compound that gives rotten eggs their smell. It's more common in well water, but it happens on municipal supply too.

How This Usually Gets Fixed

A few approaches work, depending on the cause and how bad it is:

• Flushing and disinfecting the tank to clear out the bacteria
• Replacing the anode rod with a different material, aluminum or zinc rods are less prone to this reaction than the standard magnesium rod
• In persistent cases, adjusting the water heater's temperature setting, since the bacteria involved struggle to survive above a certain point

For more on this part specifically, see our guide to anode rod replacement.

Is It Safe to Use the Water in the Meantime?

Generally yes for bathing. The smell is unpleasant, not typically hazardous at the levels found in residential hot water. Most people choose to fix it quickly simply because it's unpleasant, not because it's an emergency. That said, if the smell is strong, sudden, and paired with gas smells elsewhere in the home, that's a different situation, stop and call for an inspection rather than assuming it's the water heater.

When It's Not the Water Heater

If cold water smells the same way, or the smell is present throughout the whole house including outdoor taps, the cause is more likely somewhere else in your plumbing or the water supply itself, and it's worth a broader diagnostic rather than assuming the tank.

If you're troubleshooting other water heater symptoms too, our full water heater repair guide covers the common ones.

KCs Plumbing · water_heater_repair

A sulfur smell in your hot water almost always has a specific, known cause. We can flush the tank and swap the anode rod in a single visit in most cases.

KCs Plumbing, Heating & Drains

#17 Fawcett Road

Coquitlam BC, V3K 6V2

604-873-3753

www.kcplumb.ca

Written by the team at KCs Plumbing, Heating & Drain Services