Why Does My Water Heater Smell?

What Causes Foul Smells in Your Water Heater?

Rotten eggs, sulfur, and gas—on their own, these things already smell unappealing, but what if these scents start appearing in your water? If you have ever had this issue, you know how it can derail your day-to-day routine. Your wake-up or wind-down shower becomes something altogether unpleasant, and the smell is just as disruptive while you’re washing dishes after a nice dinner. 

If your water suddenly turns rotten on you, it’s like a lifelong friend started giving you the cold shoulder. Around this foul-smelling water, you can’t help but scrunch your nose and be a little on edge. What happened to the H2O you know and love?

Don’t worry, this smell is a common problem and doesn’t need to last forever. We’re here to tell you why your hot water heater decided to change up on you, and we can help you address its rotten attitude (and scent, of course). 

Types of Water Heater Smells to Look Out For

Rotten Egg or Sulfur Smell

If your hot water smells like rotten eggs or sulfur, this can be a result of sulfate bacteria building up in your tank. Water naturally has traces of sulfate in it, but that sulfate can evolve into hydrogen sulfide, a dangerous and smelly compound when too many sulfur-reducing bacteria grow inside your tank.

These bacteria can grow if water stays stagnant in your tank for too long. Another cause of a rotten egg/sulfur smell can be a corroded anode rod, which would need to be replaced. Rust-colored water typically accompanies a corroded anode rod.

Chemical or Bleach Smell

High levels of chlorine in your water tank can cause a chemical or bleach smell. While most water tanks will contain traces of chlorine to kill bacteria, high levels of chlorine can be harmful for consumption and general use. But if your water smells like chemicals or bleach directly after a strong storm, there is a likely explanation.

High amounts of chlorine are deposited into wells and plumbing systems directly after some storms to prevent bacterial growth. In this case, the chemical/bleach smell should disappear once the chlorine levels balance out. 

Fishy or Earthy Smell

If you’re dealing with a fishy or earthy smell, your water tank may be polluted or filled with algae, fungi, and bacteria. Routine maintenance can help prevent this smell from occurring, as fishy and earthy smells usually appear when a tank becomes neglected and its parts corrode. 

Gas or Fuel Smell

Of all the scents that can appear in your water, gas or fuel is the most concerning. If your water heater smells like gas, there may be a gas leak in your area, or your water may have been contaminated. It is important to contact a professional if you begin to smell gas or fuel in your water. 

6 DIY Fixes to Remove Bad Smells in Your Hot Water Heater

If your water heater smells, there are a few courses of action you can take, and it depends on which scent is in your water. For more concerning scents like gas, fish, and bleach, it is recommended that you contact a professional plumber to inspect and fix your tank.

For less serious scents like rotten eggs and sulfur, it is still recommended that you contact a professional, but there are ways to remove these scents on your own.

Only try these if you are comfortable with fixing a hot water tank, as this can be a dangerous task if done improperly. 

1.) Flush or Drain Your Water Heater

This is the most common way to remove bad smells from your water tank, and it should be done once or twice each year to prevent bacterial buildup. Once you drain your water heater, you need to refill it and let it run its cycle. It’s best to do this a few times so that the smell is thoroughly removed. 

2.) Add Bleach to Tank

If you tried flushing and draining your water heater but the smell still remains, try adding a small amount of bleach or white vinegar to the tank during the filling and draining process. Doing this will eliminate bacteria, and after a few rounds of flushing and draining, the smell should be gone. Letting the bleach sit for half an hour before each drain is recommended. 

3.) Add Hydrogen Peroxide

Bleach isn’t always enough. Try pouring hydrogen peroxide into your water tank, but make sure to follow these proportions: add 16 to 32 fluid ounces of 3% hydrogen peroxide for every 40 gallons of water heater tank capacity. A sticker on the side of your tank should say how many gallons it holds, and most are between 20 and 80 gallons. To add peroxide to the tank, you can pour it into the water heater’s outlet pipe opening or through the temperature and pressure valve. 

4.) Install a Water Filtration System

Sometimes, that rotten egg smell isn’t caused by your water heater. If the smell is actually coming from the water itself, you may want to install a water filtration system. These systems help filter bacteria, and while they won’t eliminate 100% of bacteria, they should certainly take care of the bad smell. 

5.) Replace Corroded Anode Rod

It is the anode rod’s job to take one for the team. It draws in bacteria from your water and prevents the rest of your water heater from corroding. Once it is fully corroded, it causes a rotten egg smell, and you’ll know that it is time for a new one. 

6.) Invest in a Water Heater Replacement

If you have tried all of the techniques above and your water is still making a stink, it may be time to welcome a new water heater into your home. Saying goodbye can be difficult, but when rotten eggs and gas are permanently in the picture, it may be the right thing to do.

Our expert plumbers at FLAME are happy to help you through the replacement process, as we can help you find the right water heater and install it, too!

Avoid Bad Hot Water Smells with Preventative Water Heater Maintenance

With regular water heater maintenance from the plumbing experts at FLAME, you may never have to ask “Why does my hot water smell?” again. Regular maintenance, including one to two annual flushes, is essential for preventing bad smells in your water. By eliminating bacterial buildup and reducing the corrosion of your anode rod, you and your water can stay on great terms and reduce future repair costs. 

Keep Your Water Heater Running Smoothly with FLAME’s Maintenance Plans

At FLAME, we offer three maintenance plans to keep your water heater happy and healthy, and you can choose whichever option suits your needs best. Since 1949, our master and journeyman professionals have been aiding the Detroit metro area, and our plumbers are here to help with 24/7 emergency service, free estimates on replacement quotes, and fair pricing.

We respect your time, and we know that if something stinks, something needs to be done about it. If your water heater smells and you don’t know why, give us a call at (888) 234-2340 or contact us online.