Why Does My Water Heater Smell?

It’s time to wash up after dinner. You turn on the hot water to rinse your dishes so you can load them in the dishwasher, and it hits you –– a foul odor coming from the faucet. What gives? Why does your water heater smell? A few different things can make the water from your water heater smell bad.

Inactive Water

Did you recently return from a vacation? Have you used no hot water for an extended period? If the water sits in the tank for a long time without any activity, it can begin to smell. The longer it sits, the greater the chance that it will develop an off smell.

Low Chlorine

If you have a well and aren’t treating the water coming out of it with chlorine, you could experience a foul odor from your water heater.

Low Temperature

Check the thermostat on your water heater. Is it below 120 degrees F? If so, that could be the culprit. Water stored at a low temperature can begin to smell.

The Underlying Problem

In most cases, the underlying problem with smelly water is bacteria. If your water sits inactive for weeks at a time, that can give bacteria a chance to thrive. If you’re not treating your well water with chlorine, naturally occurring bacteria in the water supply can colonize your water heater and cause a foul, rotten egg smell.

However, there is a possibility that the smell is from an interaction between the magnesium anode rod in your water heater and softened water (if you have a whole-home water softener). This can create the smell of rotten eggs, as well as air bubbles in the lines.

How to Tell If Your Water Heater Is the Problem

Before you try to make any repairs, identify the source of the problem. Turn on the cold water only and see if the water smells. If it does, then the water supply is the problem, not the water heater. You’ll need to treat your well water with chlorine to kill off the bacteria causing the smell. 

If it does not, then the water heater needs to be inspected. It could be related to your water softener (if applicable). It could also be that you need to increase the tank’s temperature to 140 degrees for eight hours to kill off the bacteria. In other cases, the tank may need to be flushed. Contact Elk Grove Village Sewer & Plumbing to help remove the odor from your water heater.