How to Remove Rust From Hot Water Heater: Must Know Steps!

Hot Water Heater

Is your hot water heater spewing rusty, discolored water? Rust build-up in a hot water system is quite common due to mineral deposits and corroded anode rods. In this article, we will guide you through effective methods to remove rust from your hot water heater restoring it back to optimal health.

Read on for the best preventative measures and elimination tactics that can save your system from further damage!

Key Takeaways

  • Flushing the hot water heater regularly is an effective method to remove rust and sediment buildup, improving its overall efficiency and lifespan.
  • Using a descaling solution can dissolve mineral deposits and corrosion, effectively eliminating rust buildup in a hot water heater.
  • Scrubbing with a specially formulated rust remover can help remove stubborn rust from the surfaces of a hot water heater.
  • Regularly inspecting and replacing the anode rod is crucial for preventing rust formation in a hot water heater.

Causes of Rust in Hot Water Heaters

Mineral deposits and a corroded anode rod are common causes of rust in hot water heaters. Excessive sediment buildup can also contribute to the formation of rust.

Mineral deposits

Mineral deposits are a common problem in hot water heaters, especially in areas with hard water. They form when minerals like calcium and magnesium precipitate out of the heated water and stick to the walls and other surfaces inside your tank.

Over time, these mineral layers can harden into what is called scale, which not only reduces the efficiency of your heater but also leads to rusting. The process begins by corroding the heating elements where minerals directly deposit while they heat up the water.

This corrosion ultimately leads to rusty discoloration often seen coming from tap hot water indicating a need for rust removal or possible replacement of your hot water heater. It’s essential then to regularly flush out these accumulated deposits from your tank or consider utilizing a CLR cleaner specifically designed for such tasks as it effectively dissolves calcium, lime and rust buildup saving you extra costs on energy and replacements down line.

Corroded anode rod

The anode rod in a hot water heater is an essential component that prevents the tank from rusting. Over time, however, this rod can become corroded and ineffective at its job. A corroded anode rod is often a leading cause of rust formation in a hot water heater.

When the rod starts to deteriorate, it fails to protect the tank, allowing rust to develop and potentially causing damage to the heating system.

To remove rust from your hot water heater caused by a corroded anode rod, you will need to replace the rod with a new one. This simple maintenance task can help restore your water heater’s efficiency and prolong its lifespan.

By installing a fresh sacrificial anode rod made of aluminum or magnesium, you create a barrier between the steel tank and corrosive elements present in the water.

By regularly checking and replacing your anode rod every few years or as recommended by the manufacturer, you’ll be able to prevent corrosion and subsequently avoid costly repairs or premature replacement of your hot water heater altogether.

Excessive sediment buildup

One common cause of rust in hot water heaters is excessive sediment buildup. Over time, minerals and other debris can settle at the bottom of the tank, creating a layer of sediment. This sediment can trap water against the metal surface, leading to corrosion and rust formation.

Regular maintenance and flushing the tank can help prevent excessive sediment buildup. By draining and cleaning the tank periodically, you can remove accumulated sediment and reduce the risk of rusting.

Additionally, using a descaling solution during the flushing process can dissolve any remaining mineral deposits, further protecting your hot water heater from rust formation. Taking these preventive measures will not only extend the lifespan of your hot water heater but also ensure that you have clean and rust-free hot water for all your needs.

Effective Methods to Remove Rust from a Hot Water Heater

To remove rust from a hot water heater, you can flush the tank, use a descaling solution, scrub with a rust remover, or replace the anode rod.

Flushing the tank

Flushing the tank is a simple and effective method to remove rust from a hot water heater. Here’s how to do it:

  1. Turn off the power or gas supply to the water heater.
  2. Locate the drain valve at the bottom of the tank. Attach a garden hose to the valve and position the other end near a suitable drain or outside area.
  3. Open a hot water faucet in your home to relieve pressure in the tank.
  4. Slowly open the drain valve and allow the water to flow out through the hose. Be careful as it may be hot.
  5. Once most of the water has drained, close the drain valve and remove the hose.
  6. Refill the tank by turning on both hot and cold water faucets in your home. This will help flush out any remaining sediment or rust particles.
  7. Let the water flow for several minutes until you no longer see any signs of rust or sediment.
  8. Finally, turn off all faucets and restore power or gas supply to your water heater.

Using a descaling solution

Using a descaling solution is another effective method to remove rust from a hot water heater. This solution helps to dissolve mineral deposits and corrosion, effectively eliminating rust buildup. Here are the steps to follow when using a descaling solution:

  1. Turn off the power supply or gas to the hot water heater and allow it to cool down completely.
  2. Close the cold water inlet valve to prevent any additional water from entering the tank.
  3. Attach a garden hose to the drain valve at the bottom of the tank and place the other end of the hose in a suitable drainage area.
  4. Open the drain valve and allow all the water in the tank to drain out. This will help remove any loose rust particles and sediment.
  5. Once all the water has drained out, close the drain valve and remove any remaining sediment from inside the tank.
  6. Prepare your descaling solution according to the manufacturer’s instructions. This can typically involve diluting the solution with water in a specific ratio.
  7. Pour the descaling solution into the hot water heater through either an opening on top or through a designated valve if available.
  8. Let the solution sit inside the tank for at least 1 – 2 hours, allowing it to break down and dissolve any rust or mineral deposits.
  9. After sufficient time has passed, open all hot water faucets in your home to release any built – up pressure inside the tank. This will also help flush out any remaining residue when you refill it later.
  10. Drain out all of the descaling solution by reopening the drain valve with your hose connected, making sure that all traces of rust and sediment are flushed out with it.
  11. Close all hot water faucets once again, remove your hose from t

Scrubbing with a rust remover

Scrubbing with a rust remover can be an effective method to remove rust from a hot water heater. Here are the steps to follow:

  1. Choose a suitable rust remover: Look for a rust remover specifically designed for use on hot water heaters. These products are typically available at hardware stores or online.
  2. Turn off the power and water supply: Before you begin scrubbing, make sure to turn off the power supply to the hot water heater and shut off the water valve.
  3. Protect yourself: Put on gloves and safety goggles to protect your hands and eyes while working with the rust remover.
  4. Apply the rust remover: Follow the instructions provided with the rust remover product and apply it directly to the areas affected by rust. Use a cloth or sponge to spread the product evenly over the surface.
  5. Let it sit: Allow the rust remover to sit on the affected areas for the recommended amount of time stated in the product instructions. This will give it enough time to penetrate and break down the rust.
  6. Scrub away the rust: Using a scrub brush or abrasive sponge, vigorously scrub the areas where you applied the rust remover. The scrubbing action will help loosen and remove any remaining rust particles.
  7. Rinse thoroughly: Once you have finished scrubbing, thoroughly rinse off all traces of the rust remover from the hot water heater using clean water.
  8. Inspect for remaining rust: After rinsing, carefully inspect your hot water heater for any remaining signs of rust. If there is still some present, you may need to repeat this process or try another method for removing stubborn rust.

Replacing the anode rod

To remove rust from a hot water heater, replacing the anode rod is an effective method. The anode rod is a crucial component that protects the tank from corrosion by sacrificing itself to prevent rust formation. Here are the steps to replace the anode rod:

  1. Turn off the power supply: Before starting any work on the water heater, make sure to turn off the power supply and allow the water to cool down.
  2. Locate the anode rod: The anode rod is usually located on top of the water heater and can be accessed by removing the hex-shaped head cap.
  3. Drain some water: To relieve pressure from the tank, open a hot water faucet nearby and attach a garden hose to the drain valve at the bottom of the tank. Drain several gallons of water until it runs clear.
  4. Remove the old anode rod: Use a socket wrench or a breaker bar to loosen and remove the old anode rod. Depending on its condition, it may require significant force to break loose.
  5. Inspect and measure: Take note of any visible signs of rust or deterioration on the old anode rod. Measure its length so you can choose a suitable replacement.
  6. Choose and install a new anode rod: Purchase a new anode rod that matches your water heater’s specifications in terms of material (aluminum, magnesium, or zinc), length, and diameter. Insert and tighten it securely using your wrench or breaker bar.
  7. Refill and restart: Close all valves, remove the hose from the drain valve, and carefully refill the tank with cold water through the cold-water inlet valve until it reaches normal operating levels. Finally, turn on the power supply again.

Image of anode rod with layer of rust

Preventive Measures to Avoid Rust in Hot Water Heaters

To prevent rust in hot water heaters, regular maintenance and inspections should be conducted to identify and address any potential issues. Installing a water softener can help reduce mineral deposits and corrosion, while using a sacrificial anode rod can attract rust-causing elements away from the tank.

Regular maintenance and inspections

Regular maintenance and inspections are vital to preventing rust in hot water heaters. By following these simple steps, you can keep your hot water heater in tip-top shape:

  1. Drain the tank annually to remove sediment buildup and prevent rust formation.
  2. Check the anode rod every few years and replace it if it shows signs of corrosion. This sacrificial rod plays a crucial role in preventing rust by attracting corrosive elements.
  3. Inspect the pressure relief valve regularly to ensure proper functioning. If this valve fails, pressure can build up in the tank, leading to rust and possible explosion.
  4. Examine the tank for any signs of leaks or corrosion on the exterior. Rust on the outside may indicate a problem with the tank itself and should be addressed promptly.
  5. Keep an eye out for discolored water coming from your faucets, as it may be a sign of rust inside the tank.

Installing a water softener

Installing a water softener can be an effective way to prevent rust from forming in your hot water heater. Here are some key steps to follow:

  1. Determine the size and type of water softener suitable for your hot water heater.
  2. Purchase a water softener system that meets your needs and budget.
  3. Shut off the water supply to your hot water heater.
  4. Locate the incoming cold – water pipe and install the bypass valve provided with the water softener.
  5. Connect the bypass valve to both the main cold – water supply line and the hot water outlet pipe using appropriate fittings.
  6. Install the resin tank of the water softener near your hot water heater, ensuring it is securely mounted.
  7. Connect the resin tank to the bypass valve using the provided tubing or pipes, following manufacturer instructions.
  8. Position and secure the brine tank nearby, making sure it is easily accessible for salt replenishment.
  9. Connect the brine tank to the resin tank using appropriate tubing or pipes as specified by the manufacturer.
  10. Fill the brine tank with salt pellets according to recommended dosage instructions provided by the manufacturer.
  11. Slowly turn on the cold – water supply and check for any leaks in all connections.
  12. Allow time for regeneration cycles as directed by your specific water softener model.

Using a sacrificial anode rod

One of the most effective methods to remove rust from a hot water heater is by using a sacrificial anode rod. This rod is made from a more reactive metal than the tank itself, such as magnesium or aluminum. It works by attracting corrosive elements in the water and sacrificing itself instead of the tank. Here are the steps to use a sacrificial anode rod:

  1. Purchase a sacrificial anode rod that is compatible with your hot water heater model.
  2. Turn off the power supply to the water heater and shut off the cold water inlet valve.
  3. Locate the anode rod’s access point on top of the heater, which is usually marked with a hexagonal shape.
  4. Use a socket wrench to unscrew and remove the old anode rod from its position.
  5. Inspect the condition of the old anode rod – if it is heavily corroded or worn out, it’s an indication that it has been doing its job effectively.
  6. Clean any sediment or debris from around the access point before installing the new anode rod.
  7. Apply plumber’s tape to ensure a tight seal when screwing in the new sacrificial anode rod.
  8. Insert and tighten the new anode rod into place using gentle force, being careful not to overtighten it as this may damage the threads or tank lining.
  9. Finally, turn on the cold water inlet valve and restore power to your hot water heater.


1. Can I remove rust from a hot water heater myself?

While it is possible to remove rust from a hot water heater yourself, it is recommended to hire a professional plumber or technician who has the expertise and proper tools to safely and effectively address the issue without causing further damage.

2. What are some effective methods for removing rust from a hot water heater?

Professional plumbers often use techniques such as descaling, chemical treatments, or replacing corroded components to remove rust from a hot water heater. The best method will depend on the severity of the rust and the specific type of water heating system.

3. How can I prevent future rusting in my hot water heater?

Regular maintenance is important to prevent future rusting in your hot water heater. This includes flushing out sediment regularly, installing sacrificial anode rods inside the tank, ensuring proper ventilation around the unit, and addressing any leaks or moisture issues promptly.

4. Is it necessary to replace my hot water heater if it has significant rust?

If your hot water heater has significant rust that cannot be effectively removed or repaired by professionals, replacing the unit may be necessary. A rusty tank can lead to leaks or even burst pipes, so it’s crucial not to ignore severe corrosion issues for safety reasons.


In conclusion, knowing the effective methods to remove rust from a hot water heater is crucial in maintaining its longevity and performance. By regularly flushing the tank, using descaling solutions or rust removers, and replacing the anode rod, you can effectively eliminate rust buildup.

Additionally, taking preventive measures such as regular maintenance and inspections, installing a water softener, and using sacrificial anode rods can help prevent rust formation in the first place.

With these tips in mind, you can ensure your hot water heater remains in top condition for years to come.