How To Remove Smells From a Water Tank: Seven Methods

Turning on your tap only to be hit with a foul odor is a nightmare. Whether it smells like rotten eggs, sewage, or heavy chemicals, that stench usually points to an issue inside your water tank or plumbing system.

You need clean, odorless water for cooking, bathing, and drinking. We have researched the best ways to troubleshoot and fix these issues yourself.

In this guide, we break down seven effective methods to remove smells from a water tank, help you identify the specific cause, and let you know when it is time to call a pro.

Why Does My Water Tank Water Smell?

Several different contaminants can ruin your water quality. Here are the most common culprits and what they mean for your plumbing:

• Rotten eggs or sewage: Sulfur bacteria is the most common cause. This bacteria grows in the water supply, the drain, or the heater itself. It often results from stagnant water or a degraded anode rod reacting with the water.
• Bleach or chemicals: High chlorine levels are usually to blame. While chlorine treats water, levels over 2.0 parts per million can cause strong odors. Test this with a water quality tester.
• Fishy odors: Decaying organic matter usually creates this scent. It often accumulates in the drain, well storage, or pressure tank. Surface drainage pollution can also be a factor.
• Earthy or musty scents: Iron bacteria is the main suspect here. While generally not harmful to your health, it ruins the taste of your water.
• Gasoline or fuel: This is a critical warning sign. A leaking fuel tank or agricultural runoff may have contaminated your water supply. Stop drinking the water immediately and contact your county health department.
• Electrical or burning smells: A short circuit in the heating element or wiring can cause this. Unplug the heater immediately and call a technician.

Identify the Odor Source

You need to pinpoint where the smell originates before you can fix it. The diagnosis starts at the faucet.

First, determine if the smell comes from the water heater or the water source itself. Turn on a faucet and let it run.

If the odor disappears after running the tap for a few minutes, the issue is likely in the specific pipes or fixtures supplying that faucet, not the whole system.

However, if the smell is constant, check the temperature. Turn on only the hot water. If the smell is present, turn it off and test only the cold water.

If only the hot water smells, the problem is inside your water heater. You can use the methods below to fix this.

If both hot and cold water smell, the issue lies with your water source (municipal supply or well). You will need to contact your local water utility company to report the issue.

How To Remove Smell From a Water Tank

If you have isolated the problem to your hot water tank, you can fix it. Use these seven methods to sanitize your system and restore fresh water.

Gather Your Supplies

Prepare these tools before you start:

• Garden hose.
• Bleach or hydrogen peroxide.
• Measuring jugs.
• Replacement anode rod.
• Flathead screwdriver.
• 1-1/16th-inch socket.
• Cheater bar.
• Teflon tape.
• Socket wrench.
• Pipe wrench or channel lock.
• Rags and towels.

Sanitize the Tank

Killing the bacteria inside the tank is the most effective first step. You can use hydrogen peroxide or chlorine bleach for this process.

1. Shut off the water: Close the cold water valve entering the tank or the main water supply valve.
2. Relieve pressure: Open a nearby hot water faucet to prevent air locks. detailed instructions. Then, open the temperature and pressure (T&P) valve on top of the tank.
3. Power down: Turn off the tank. Flip the breaker for electric heaters. For gas, turn the dial to “Pilot” or “Vacation” mode.
4. Drain the tank: Connect a garden hose to the drain valve at the bottom of the tank. Run the other end to a floor drain or sump pump. Open the valve and drain enough water to make room for the cleaning solution.
5. Add the sanitizer: Remove one of the water pipes (anode rod hole or outlet pipe) on top of the tank. Pour in your solution. Use ¾ cup of bleach for a 40-gallon tank. If using 3% hydrogen peroxide, use roughly 2 to 4 pints per 40 gallons.
6. Refill the tank: Reconnect the pipe and close the drain valve. Turn the cold water supply back on to fill the tank.
7. Let it sit: Once the tank is full, close the faucets and let the solution sit inside the tank for one to three hours.
8. Flush the system: Turn the water supply back on. Open all hot water faucets in your house. Let the water run until the smell of bleach or peroxide is completely gone.
9. Check the water: Smell the water. If the odor is gone, you are all set. If it persists, move to the next method.

Replace the Anode Rod

The anode rod is a “sacrificial” metal rod that attracts corrosion to save the tank walls. When this rod degrades, the reaction can create a rotten egg smell. Replacing it is a standard maintenance task.

Choose the right rod for your needs:

• Aluminum: Good for hard water areas but can accumulate sediment.
• Magnesium: Standard for most tanks but degrades quickly in hard water.
• Zinc/Aluminum: The best option for fighting odors. The zinc helps mask sulfur smells.

Follow these steps to replace the rod:

1. Turn off power and water: Shut off the electricity or gas and close the cold water inlet valve.
2. Drain slightly: Attach a hose to the drain valve and let out about two gallons of water to lower the pressure.
3. Locate the rod: Find the hex head on top of the tank. It may be under a plastic cap.
4. Remove the old rod: Use a 1-1/16-inch socket and a cheater bar for leverage. Unscrew the rod and lift it out. Be careful; it may be hot and deteriorated.
5. Install the new rod: Wrap Teflon tape clockwise around the threads of the new rod. Insert it into the tank and tighten it securely with your socket wrench.
6. Refill and test: Turn the water supply back on. Open a hot water faucet to release air. Check the rod connection for leaks before turning the power back on.

Flush Your Water Heater

Sediment buildup provides a breeding ground for bacteria. Flushing your tank twice a year keeps the water fresh and extends the heater’s life.

1. Cut the power: Turn off the breaker or set the gas dial to pilot.
2. Close the inlet: Shut off the cold water supply valve.
3. Attach a hose: Connect your garden hose to the drain valve and route it to a safe drainage area.
4. Drain the tank: Open the drain valve. Open a hot water faucet elsewhere in the house to help the water flow. Let the tank empty completely. Be careful, as the water is scalding hot.
5. Rinse the sediment: Turn the cold water supply on for 20 seconds to stir up sediment at the bottom, then turn it off. Repeat this until the water flowing out of the hose runs clear.
6. Refill the system: Close the drain valve and disconnect the hose. Turn the cold water supply back on. Leave the house faucet open until water flows steadily, then turn the power back on.

Raise Your Water Temperature

Bacteria, including Legionella and sulfur bacteria, thrive in lukewarm water. cranking up the heat for a short period can pasteurize the tank.

Gas Water Heater

1. Find the dial: Locate the temperature knob at the base of the unit.
2. Increase heat: Turn the dial to “High” or approximately 140 degrees Fahrenheit.
3. Wait: Let the tank run at this temperature for several hours.

Electric Water Heater

1. Access the thermostat: Turn off the power at the breaker. Remove the access panels on the side of the tank and peel back the insulation.
2. Adjust the screw: Use a flathead screwdriver to turn the thermostat dial to 140 degrees Fahrenheit. If you have two thermostats, adjust both.
3. Close up: Replace the insulation and panels, then flip the breaker back on.

Install a Water Softener

Hard water contributes to scale buildup, which traps bacteria. A water softener removes minerals, improves taste, and helps prevent odors. This is an advanced DIY project.

1. Prep the location: Choose a spot near the main water line and a drain.
2. Cut the main line: Shut off the house water and drain the pipes. Cut the main supply line to accommodate the softener connections.
3. Connect the softener: Install the bypass valve on the unit. Connect the hard water line to the inlet and the house supply line to the outlet using compression fittings or push-to-connect adapters.
4. Run the drain: Connect the drain tube from the softener to a floor drain or utility sink.
5. Fill and start: Add salt to the brine tank according to the manual. Turn the water back on slowly and plug in the unit.
6. Configure: Set the hardness level and run a manual regeneration cycle to flush the system.

Replace the Water Heater

If your tank is over 10 years old and the smell persists despite cleaning, the inner lining may be compromised. Replacing the unit is often the most cost-effective solution in the long run.

While we recommend professional installation, experienced DIYers can swap a tank by draining the old unit, disconnecting water and gas/electric lines, and installing the new unit with fresh flexible supply lines and pipe dope on gas connections. Always leak-test gas connections with soapy water before igniting.

Treat the Water Source

If the smell comes from both hot and cold taps, the issue is not your tank.

• Municipal Water: Contact your water provider. They can flush the main lines or investigate contamination.
• Well Water: You may need shock chlorination for your well. Contact a licensed well driller or pump installer to handle this safely.

What to Do If the Water Still Smells

If you have flushed the tank, replaced the anode rod, and cranked the heat, but the odor remains, you have a deeper plumbing issue.

• Install a filtration system: A whole-home carbon filter can remove sulfur smells and chlorine.
• Call a plumber: There may be dead legs in your piping (unused pipes where water stagnates) that need to be removed.
• Test for contamination: Send a sample to a lab to check for harmful bacteria or chemicals that standard cleaning cannot fix.

Water Tank Maintenance Tips

Preventing odors is easier than removing them. Follow this maintenance schedule to keep your water fresh:

• Flush annually: Drain the tank once a year to remove sediment. If you have very hard water, do this every six months.
• Inspect the anode rod: Check the rod every three years. If the core wire is visible or it is coated in calcium, replace it immediately.
• Keep it moving: If you go on vacation, stagnant water can develop odors. Flush the taps for a few minutes when you return.
• Check the temp: Keep the thermostat at 120 degrees Fahrenheit for daily use. This is hot enough to inhibit most bacteria but safe enough to prevent scalding.

FAQs

Can I Shower If My Water Smells Like Rotten Eggs?

We recommend avoiding it. While the smell is often just sulfur bacteria, it indicates the water is not clean. There is a risk of other contaminants being present. If the smell is severe, wait until you have sanitized the tank or identified the source before showering or brushing your teeth.

Does Boiling Water Remove Sulfur Smells?

No. Sulfur boils at 832 degrees Fahrenheit, which is far higher than the boiling point of water ⁽¹⁾. Boiling might release some of the gas into the air (making your kitchen smell worse), but it will not remove the sulfur content from the liquid.

How Do You Get Rid of a Sewer Smell In an RV?

First, flush the black water tank and clean the toilet bowl thoroughly. Ensure you are using the correct holding tank chemicals to break down waste and control odors. Check for clogs and ensure your RV’s roof vent is clear of debris. If the smell persists, sanitize the fresh water system with a bleach solution.

Can I Use Vinegar To Clean My Water Tank?

Yes, distilled white vinegar is a safe cleaner and descaler. However, it is less cost-effective for large tanks. You typically need a 1:1 ratio of vinegar to water for deep cleaning. For a 40-gallon tank, buying 20 gallons of vinegar is expensive and impractical compared to using chlorine bleach or hydrogen peroxide.

Why Does My Water Smell Like Rotten Eggs?

This specific smell is caused by hydrogen sulfide gas. This gas is produced by sulfur bacteria reacting with the magnesium or aluminum anode rod in your water heater. It can also occur naturally in groundwater. Replacing the standard anode rod with a zinc-aluminum alloy rod usually solves this specific odor problem.

Fresh Water Awaits

You don’t have to live with smelly water. Start by identifying if the odor is in the hot water tank or the main supply. In most cases, a simple tank flush and a hydrogen peroxide treatment will solve the problem.

If the rotten egg smell keeps coming back, swap your anode rod for a zinc-aluminum model. Regular maintenance is key, flush your tank annually and keep an eye on leaks to ensure your water stays clean and safe for years to come.