Why Does My Hot Water Smell Like Rotten Eggs? (And How to Fix It)

Why Does My Hot Water Smell Like Rotten Eggs?

In order to determine where the sulfur smell is coming from, run the hot water for an extended period. Does the smell lose some of its potency over time? If it does, the cause lies in the plumbing system. If the smell doesn’t go away at all, then it’s coming from the groundwater and likely affects both your hot water and cold water. 

Damage Caused By Rotten Egg Smell in Hot Water

Sulfur bacteria in your drinking water isn’t harmful in itself. It is safe to drink (even if not preferable) and doesn’t cause direct damage to your water heater. However, hydrogen sulfide gas can prove harmful in high concentrations. 

Sulfur bacteria can also encourage the growth of other more harmful bacteria inside your water heater. The presence of bad bacteria can cause corrosion and ugly black stains. 

Other chemicals and minerals commonly found in water include:

• Lead 
• Nitrate
• Arsenic
• Coliform bacteria
• VOCs
• Fluoride

You can’t smell, taste, or see most of these substances, so you will need to test your water quality to get a complete report. You can buy water quality tests online or hire professional services. 

How to Fix Rotten Egg Smells Coming From Hot Water

Rotten egg smell coming from your hot water doesn’t necessarily mean that you can’t drink it. However, you probably prefer to drink water without the additional odor.

These techniques will remove rotten egg smell coming from your hot water heater. 

Replace Anode Rod With Zinc Anode Rod 

Every storage tank water heater has an anode rod. The anode rod attracts corrosive materials, sacrificing itself instead of the tank material. 

There are three types of sacrificial anode rods that generate different results:

• Aluminum 
• Magnesium
• Zinc 
  

Aluminum anode rods are the least expensive option. They handle hard water the best, but they don’t attract all of the corrosive material. 

Magnesium anode rods work better, but they cost more and require replacement more often. 

Zinc anode rods, in particular, eliminate sulfur in the hot water heater thanks to the presence of sulfate reducing bacteria, also eliminating the rotten egg smell. 

After you change the anode rod, you should flush the water heater to remove the excess sulfur bacteria in the water heater tank. You should notice a difference the next time you use your hot water. 

Learn more about anode rods in our blog post Water Heater Anode Rods 101. 

Increase Hot Water Temperature 

You can kill bacteria with high temperatures. To kill the bacteria, increase the temperature of your water heater to 160°F for 2 - 3 hours. If your water heater doesn’t go up to 160°F, set your water heater to 140°F for about 8 hours. Sulfur bacteria will not die in 120°F water (the recommended water heater temperature). 

After you kill the bacteria, flush the water heater to remove any remaining odor.

Take proper precautions before increasing the temperature of your water heater. Water at 160°F presents a serious scalding hazard. 

Water Filtration

When the sulfur exists in the groundwater, you’ll need to install a water purifier to resolve the issue. A water purifier will remove the bacteria from the water before it enters your water heater. Some systems use chlorine in a process known as shock chlorination to remove sulfate from the water source. 

You will need to buy a water treatment device and have it installed on your main water line. At this time, U.S. Water Heating Solutions does not offer water treatment services. 

U.S. Water Heating Solutions

U.S. Water Heating Solutions can diagnose the foul odor coming from your water heater. We can then offer solutions based on your unique circumstances. 

We can always flush your water heater for you. In some cases, we will be able to change out the anode rod for you. 

If your water heater contains a rotten egg smell, call us today at 833-879-4776 or request a quote for service.