Get Rid of the Hot Water Rotten Egg Smell: Effective Strategies for Your Water Heater

Are you tired of that unpleasant hot water rotten egg smell coming from your water heater? We’ve got you covered!

In this comprehensive guide, we’ll not only help you understand why this stinky sulfur smell occurs but also provide you with practical troubleshooting and repair solutions to get rid of it. No more holding your nose while taking a shower!

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With our easy-to-follow steps, you’ll be able to eliminate the annoying odor and restore fresh, clean water to your home.

Say goodbye to that unwelcome scent and say hello to a more enjoyable experience.

How to Remove Hot Water Rotten Egg Smell From a Water Heater: Things to Consider

  1. What is the rotten egg smell?
  2. What is the cause of a problem?
  3. Importance of addressing the problem
  4. Is hydrogen sulfide gas harmful?
  5. Troubleshooting and repair tips
  6. Prevention

What Is the Hot Water Rotten Egg Smell?

The rotten egg smell is a distinct, sulfurous odor that can be detected in hot water from your heating device. It is often described as a pungent and unpleasant aroma resembling rotten eggs or sulfur. This smell can make the water unappealing for various domestic uses.

What Causes Hot Water Rotten Egg Smell in Water Heaters?

A possible cause of the sulfur or hot water rotten egg smell is the bacteria that develop in the tank sediments. These sediments provide a breeding ground for bacteria that feed on hydrogen sulfide gas (H2S), which is often created from the decay of the anode rod and other factors, including:

  1. Bacterial growth: Bacteria present in the tank can produce hydrogen sulfide gas as they metabolize sulfur-containing compounds.
  2. Anode rod reaction: The decay of the anode rod, typically made of magnesium or aluminum, can create the problem with this gas.
  3. Sulfur contamination: If the water supply contains sulfur or sulfur compounds, it can lead to the presence of hydrogen sulfide gas in the tank.

Since sulfur, hydrogen, and bacteria are the main culprits behind the production of hydrogen sulfide gas, removing any of these elements should effectively eliminate the unpleasant odor.

It’s worth noting that if you’re using a public (municipality) water supply that undergoes proper chlorination, the bacteria responsible for the odor will be eradicated, reducing the likelihood of encountering this problem. However, if you rely on well water, it’s possible that the issue might persist and require attention.

Understanding and addressing the source of the smell is crucial to restore water quality and ensure a pleasant user experience.

Impact on Water Quality and User Experience

Addressing the hot water rotten egg smell is of utmost importance due to its impact on the quality and user experience.

Firstly, the presence of the foul odor indicates potential issues with water quality. Since the smell is often caused by hydrogen sulfide gas, which can be an indicator of bacterial growth or sulfur contamination, consuming or using water with such odors can be unappetizing and may raise concerns about the safety and cleanliness of the plumbing system.

Moreover, the unpleasant smell can significantly affect the user experience. Using hot water for bathing, cooking, or drinking that carries a rotten egg odor can be off-putting and discomforting. It can reduce the enjoyment and satisfaction of everyday activities that rely on a reliable and pleasant water source.

Addressing the problem promptly ensures that water quality is restored to its optimal state, free from unwanted odors and potential contaminants.

Is Hydrogen Sulfide Gas Harmful?

Hydrogen sulfide gas is easily recognizable due to its distinctive odor, which can noticeably impact the taste and smell of water. The presence of developed bacteria may also lead to black deposits, resulting from pipe and fitting corrosion. It is important to note that extremely high concentrations of hydrogen sulfide gas can be toxic.

The combination of increased sulfur levels, the presence of hydrogen, low dissolved oxygen in water, and temperatures below 138°F or 59°C create an environment conducive to significant bacteria growth.

Is it harmful?

While the rotten egg odor caused by hydrogen sulfide gas may be unpleasant, it is not harmful to health, posing no direct risks. However, when using hot water for activities such as showering or dishwashing, the strong odor can be irritating.

It’s worth mentioning that if the sulfur odor originates from the sewage or potentially hazardous chemicals in the water supply, contacting the utility company or municipality is advisable.

Troubleshooting and Repairing Tips

To identify the source of the smell, perform a simple test: run the hot water faucet exclusively for a few minutes and assess if the odor is noticeable. Repeat the process with the cold water faucet and observe if the smell persists. Take note of whether the smell is consistent in both taps or limited to one source. This information will help determine the underlying issue and guide you in taking appropriate troubleshooting steps.

Just relying on a water softener to address the issue of hard water is not a comprehensive solution. In fact, it can potentially exacerbate the problem, especially when dealing with well water or extended periods of water stagnation.

It’s important to understand that the rotten egg smell stems from a chemical reaction involving the decomposition of the sacrificial anode, typically made of magnesium or aluminum, and its surrounding components. Consequently, removing the anode rod is not recommended, as it can have adverse effects.

It’s crucial to note that completely removing the anode rod will void the warranty and shorten the lifespan of the tank.

A simple and cost-effective solution for the hot water rotten egg odor is frequent flushing of the sediments from the tank. This not only helps improve performance and efficiency but also helps alleviate the issue. Using chlorine bleach or peroxide during the flushing process can be effective (see below).

Furthermore, some manufacturers, like CorroProtec, claim that their powered anode rods can eliminate the sulfur smell within 24 hours, prevent tank corrosion, and extend the overall lifespan of the heating unit.

How to Flush a Water Heater Using Peroxide or Bleach

Flushing a water heater using peroxide or bleach can help eliminate odors and disinfect the tank. Here’s a step-by-step guide:

  1. Turn off the power supply: Before starting the flushing process, ensure the heater is turned off to avoid any accidents or damage.
  2. Prepare the solution: For peroxide, use 3% hydrogen peroxide, and for bleach, use household chlorine bleach (non-scented). Refer to the following ratios: For peroxide: Use 1 pint (16 ounces) of peroxide for every 10 gallons of water in the tank. For bleach: Use 1/4 cup of bleach for every 10 gallons of water in the tank.
  3. Connect a hose: Locate the drain valve at the bottom of the heater and attach a garden hose to it. Make sure the other end of the hose is positioned to safely drain the water outside or into a suitable drain.
  4. Open the drain valve: Carefully open the drain valve and allow the water to flow out. This will help remove any sediments and debris present in the tank. Be cautious as the water may be hot.
  5. Add the solution: Close the drain valve once the water has mostly drained out. Pour the prepared peroxide or bleach solution into the tank through the heater’s opening.
  6. Fill the tank: Turn on the cold water supply to the unit, allowing the tank to fill partially.
  7. Let the solution sit: Allow the peroxide or bleach solution to sit in the tank for a few hours or as recommended by the product instructions. This will help disinfect and eliminate any odor-causing bacteria.
  8. Flush the tank: After the designated time has passed, open the drain valve again and let the solution drain completely. Ensure that all the solution is flushed out before proceeding.
  9. Refill and flush: Close the drain valve and turn on the cold water supply to refill the tank. Open several hot water faucets in your home to purge any remaining solution from the plumbing system. Let the water run for a few minutes until you no longer detect the smell of peroxide or bleach.
  10. Restore power: Once the tank is refilled and the water runs clear, you can safely turn the power supply back on to the heater.

Either using chlorination or peroxide flush, this is a surface treatment where repeated trials are recommended for highly infected plumbing systems.

How to Get Rid of Hot Water Rotten Egg Smell by Replacing an Anode Rod

Every water heater with the metal tank is equipped with the anode rod, usually called the sacrificial rod, and is used to protect the steel metal tank from corrosion and rust. Because of its nature to dissolve due to the aggressive water action, it sacrifices itself to protect the tank.

If the anode rod is causing issues, there are a few options you can consider:

  1. Replace the anode rod: If the anode rod is heavily corroded or depleted, replacing it with a new one is often the best course of action. Choose a suitable anode rod that is compatible with your model and follow the manufacturer’s instructions for installation.
  2. Use a different type of anode rod: If the standard sacrificial anode rod is causing odor or corrosion problems, you may explore alternative options. For example, there are powered anode rods available that use electrical currents to prevent corrosion and eliminate odor issues.
  3. Install a plastic-lined tank water heater: As mentioned earlier, another solution is to consider replacing your water heater with a plastic-lined tank-type heater. These tanks are designed to minimize odor problems and offer increased durability and longevity. Rheem Marathon is one example of a plastic-lined model that you can consider.


Prevention and regular maintenance are key to ensuring that the rotten egg smell does not recur in your heater. Here are some preventive measures and maintenance tips to consider:

  1. Flush the tank regularly: Flushing the heater at least once a year helps remove sediment buildup and reduces the likelihood of bacterial growth. Follow the manufacturer’s instructions or refer to the previous section on how to flush the water heater effectively.
  2. Check the anode rod: Inspect the condition of the anode rod annually and replace it if necessary.
  3. Maintain proper temperature settings: Set the temperature to at least 140°F (60°C) to discourage bacterial growth. However, be cautious not to exceed the safe temperature limit to prevent scalding accidents.
  4. Turn off the unit when you’re away: If you’re going on vacation or won’t be using the water heater for an extended period, it’s advisable to turn off the power to conserve energy and prevent the accumulation of hydrogen gas. This is particularly important if you have hard water, as it can aggravate the issue.
  5. Use a water softener: If you have hard water, consider installing a water softener to reduce mineral buildup in the tank. This can help minimize the conditions that promote bacterial growth and the formation of hydrogen sulfide gas.
  6. Regularly inspect and clean plumbing fixtures: Check and clean aerators, showerheads, and other plumbing fixtures to prevent mineral deposits and bacterial growth.


Removing the hot water rotten egg smell from your water heater requires time and persistence. It may take several attempts and ongoing maintenance to fully eliminate the odor. If regular maintenance is not performed as recommended, the smell could return, sometimes within a few weeks. In such cases, you can repeat the sanitizing or other procedures outlined in the previous sections to address the issue effectively.

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