How to Remove and Prevent Rust in a Water Heater

Unwanted water and rust on your water heater can be a major nuisance. We depend on our water heaters daily, using it sometimes multiple times a day. Regular maintenance is necessary to keep your water heater working and rust-free.

In order to eliminate and prevent rust in a water heater and make sure it is running smoothly, make sure the rod is inspected once a year. Another way to prevent rust is to make sure the water heater is regularly flushed.

There are a few more tips and tricks to help you prevent and remove rust from your water heater. Keep reading for everything you need to know about anode rods and preventing rust. 

How to prevent and remove rust from a water heater.

Inspect (and Replace) Your Anode Rod

Anode rods fit inside the water tank itself and are there to prevent rusting. The rod may deteriorate over time, so it is important to regularly inspect your rod.

The anode rod is one of the biggest determiners of how long your water heater will last. It protects the heater and prevents rust through a process known as electrolysis. Basically, the rod will attract the rust and damage, protecting the metal wall of your water heater tank.

As the anode rod takes on rust, it can deteriorate and corrode. This is why it is important to check on your anode rod regularly. Most often, damage to a water heater is caused by damage to this rod.

If you check your anode rod regularly, you will be able to see if it has been corroded. When your anode rod has been rusted or corroded from top to bottom, you will need to replace it.

Kinds of Anode Rods

There are three kinds of anode rods. These include aluminum, magnesium, and zinc.

Zinc rods are best for water that has a sulfuric odor; aluminum is best for hard water; and magnesium is best for soft water.

Instructions for Replacing Your Anode Rod

  1. Before replacing your rod, shut off your water. You will also want to shut off your home’s circuit breaker, as well as the thermostat on your home’s gas.
  2. Find the anode rod. Check your water heater manual to determine where this will be on your unit— there should be a clear diagram.
    Most water heaters have the anode rod located on the top of the water heater. Most water heaters have the anode rod connected to the hot water line.
  3. The next step is to drain the water from your water heater. Locate the drain valve on your water heater— this should be towards the bottom. Some water heaters will have a cover over the valve opening.
  4. Attach a garden hose to the drain valve, and place the other end of the hose somewhere where the water can drain safely. Be sure to be careful because the water can be very hot. Near the bottom of the tank, locate the tank drain valve and attach a standard garden hose to the drain valve.
    Be aware that some models may have a cover over the valve opening.
  5. Place the other end of the hose in a floor drain or on a driveway where it can drain safely. If necessary, buckets can be used, but be careful not to be burned by the hot water as you work. You only have to drain to just below where the rod sits.
    To drain your tank faster, open the water heater’s drain valve and hot water valve. This will help relieve pressure.
  6. Now it’s time to remove the rod. Use a socket wrench or a boxed end wrench to remove the anode rod. This will involve twisting; if the rod is tough, you may want to bend or even cut the rod to remove it.
  7. Use the same wrench to install the new rod.
  8. Turn back on the power, water, and gas.

Flush Your Water Heater Tank

Most water heaters have a big, insulated tank to make sure that there’s enough hot water to use every day, multiple times a day. With such a large amount of water, natural minerals like sand and grit can begin to accumulate and collect at the bottom of your tank.

Sediment is natural, and over time can settle at the bottom of your water heater tank. To prevent this, your tank should be flushed regularly. Too much sediment can prevent your water heater from working properly.

Sediment can also interfere with how efficient your water heater will be. In a gas water heater, sediment can cause cracking and popping sounds.

How Often Should You Flush It?

Most water heaters need to be regularly drained. How often depends on a variety of factors, including your water source. If your water is sourced from a well or if your local water has a high sediment content, you will want to flush your water heater tank more frequently.

Generally speaking, your water tank should be drained once a year.

Instructions for Draining the Tank

  1. Turn off the water supply to your water heater tank, as well as the gas supply valve.
  2. Turn off the water heater thermostat. You want to be sure that the water heater doesn’t turn on once the water is emptied, as that can cause major damage to the tank.
  3. Connect a garden hose to the valve. This should be located near the bottom of the tank. Be sure the other end of the house is placed somewhere where the water can drain safely.
  4. Open the hot water faucets in your house. This will help speed up the draining process, as it relieves pressure on the system.
  5. Open the water heater’s drain valve. The tank will begin to drain through the hose. Be sure to keep an eye on this process to make sure everything drains smoothly.
  6. Once the tank is drained, turn the cold water back on. This will help flush the sediment that has collected at the bottom of your tank.
  7. Disconnect the hose and use a vacuum to suck the sediment out of the drain valve.
  8. Once you have closed the drain valve, you can turn your water back on.
  9. Leave the hot water faucets on until water runs out of them. Don’t be alarmed by any sediment that comes out at first— this is the last of the sediment being flushed through the system.
  10. Reset the water heater’s thermostat to your desired setting. Within 15-20 minutes you should have hot water up and running again. Remember, the water will be scalding hot, so be careful to avoid it while draining your tank. If needed, consult a professional.

Add a Water Softening or Filtration System

Rust appears when there is too much iron in your water. Iron is natural, and it is common for iron to appear in your water. While the iron and resulting rust are not toxic, the rust can cause damage to your water heater tank.

Water softeners can help prevent iron from building up in your tank. The most common kind of water softener is a salt-based softener. The system introduces sodium into the water, which alters the water’s chemical balance, effectively altering the iron content.

It is possible to install water softeners yourself, but you might want to consult a professional plumber just to make sure everything is running smoothly.


The best way to prevent rust from accumulating on your water tank is routine maintenance. Be sure to check on your tank and its anode rod regularly.

See also: Best Wire Brushes for Rust Removal

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