How To Clean and Flush a Water Heater [The Easy Way]

Most water heaters will need cleaning and sediment flushing to remain functioning as long as possible. If you have a water heater that needs to be cleaned, there are a couple of ways to clean it.

However, not all water heaters function the same way. Electric heaters operate slightly differently than gas heaters, as with tank water heaters versus tankless water heaters. The type of water heater you have will dictate how you clean it and how often to clean it to prolong its life and avoid the most common water heater problems.

How To Clean Different Types Of Water Heaters?

The general concept for cleaning a water heater is similar for all types of water heaters.

The process will vary by type, but regardless of the type you must always prepare first by doing the following: (Disclaimer)

1. Gather necessary tools and materials: Before beginning the cleaning and flushing process, gather all the necessary tools and materials. This may include a screwdriver, a bucket, a pipe wrench, a garden hose, and any cleaning solutions or chemicals recommended by the manufacturer.
2. Turn off the power or gas supply: To avoid accidents, it’s important to turn off the power or gas supply to the water heater before cleaning. You can turn off the breaker at the electrical panel for an electric water heater. You can turn the knob to the pilot position for a gas water heater and ensure that the pilot light is out.
3. Allow the water to cool down: Water heaters contain very hot water, ensure the water has cooled down before starting the cleaning process.
4. Turn off the water supply to the water heater: Turning off the water supply will prevent fresh water from entering the tank during cleaning and flushing.
5. Read the manufacturer’s instructions: It’s important to refer to the manufacturer’s instructions for specific instructions on how to clean and flush your particular water heater model. As some brands may have different instructions for their units.
6. Use caution and proper protection: when working with any chemicals or cleaning solutions, use caution and wear proper protection such as gloves, goggles, and a mask.

Once you have gathered all the necessary tools and materials, turned off the power and water supply, and drained the hot water tank, you are ready to begin cleaning and flushing your water heater. Remember to refer to the manufacturer’s instructions and use caution when working with the unit to ensure that the process is done safely and effectively. Ok, now that you are armed with the basics and safety recommendations, let’s get into it…

Cleaning An Electric (Tank)

A standard electric tank water heater involves three garden hoses, two buckets, and a cleaning solution that is safe to use on water heaters. 

You first want to shut off the water heater, the power supply, and the circuit breaker. 

Here are the general steps to attach a garden hose to a water heater in order to drain it:

1. Locate the drain valve: The drain valve is typically located at the bottom of the water heater, it is a small valve that is typically bronze or brass in color.
2. Attach the garden hose: Screw one end of the garden hose onto the drain valve. Make sure the connection is tight to prevent any leaks.
3. Run the other end of the hose: Run the other end of the garden hose to a nearby drain or outside to a suitable area where the water can be safely drained.
4. Open the valve: Slowly open the drain valve to allow the water to flow out of the tank and into the garden hose. Be sure to have a bucket or container ready to catch the water if the garden hose does not reach the drainage location.
5. Drain the water: Allow the water to flow out of the tank until it stops running. This may take a few minutes depending on the size of the tank. Once all the water has been drained, close the drain valve.
6. Flush the tank: After draining the water, you can flush it with fresh water to remove any remaining debris or sediment.
7. Disconnect the hose: Once the flushing is finished, make sure the drain valve is closed then disconnect the garden hose from the water heater.

It is important to keep the valve open while draining to avoid any backflow, also it’s important to make sure that the hose runs downhill to avoid any issues with water not flowing properly. As well as make sure to have a bucket or container nearby to catch any overflow or leaks.

Next, here are the general steps to turn the water supply back on after flushing a water heater:

1. Close the drain valve: Before turning the water supply back on, close the drain valve tightly to prevent any water from leaking.
2. Turn on the water supply: Locate the main shut-off valve for the water supply to the water heater, it’s usually found near the water heater or where the water line enters the house, turn the valve handle clockwise to open the valve.
3. Check for leaks: After turning on the water supply, check for any leaks around the drain and main shut-off valve.
4. Fill the tank: Once the water supply is turned on, the water heater tank will begin to fill with fresh water. As the water is filling, the air in the tank will be displaced through the pressure relief valve, the valve may make noise, this is normal. Wait until the tank is full, this can take a bit of time.
5. Check the pressure: After the tank is full, check the gauge to ensure it is at the correct pressure. If the pressure is too high, you can release it by slightly opening the pressure release valve, then close it again.
6. Turn on the power or gas: Once the tank is full and the water pressure is correct, turn the power or gas supply back on. For electric water heaters, turn on the breaker at the electrical panel. For gas water heaters, turn the knob to the “On” position and relight the pilot light if necessary.
7. Test the water heater: After turning on the power or gas, allow the water to heat up and test the hot water to ensure that it is working properly.

It’s important to note that before turning the water supply back on, ensure that the drain valve is closed tightly to prevent any water from leaking out and check for any leaks around the drain valve and the main shut-off valve, also refer to the manufacturer’s instructions.

Cleaning A Tankless Water Heater

Steps: (further instruction for each step below)

1. Turn off power and gas/circuit breaker and allow water to cool.
2. Turn off cold water valve, hot water valve, and inlet valve.
3. Remove purge port caps on hot and cold ports.
4. Attach washing machine hoses to hot outlet port valve and cold water inlet valve.
5. Open purge ports and allow water to flow into a large bucket.
6. Fill the bucket with 4 gallons of white vinegar and attach a submersible pump.
7. Run the pump for 40-90 minutes, depending on buildup.
8. Remove the water heater faceplate and air filter, rinse and replace.
9. Turn off pump and remove it from the bucket.
10. Empty the bucket and place it under the water heater.
11. Open the water valve and let it run for a few minutes, then close it.
12. Unscrew the water filters, rinse and replace them.
13. Attach caps back onto the ports, turn on valves and power/gas.
14. Turn on water heater to restore full operation.

For a tankless water heater, you will need a large bucket, two washer hoses, a safe cleaning solution, and a pump. 

First, turn off the power to the water heater. Then, turn off the gas supply (if it’s a tankless gas water heater) or turn off the circuit breaker (if it’s electric). Allow time for the water to cool before moving further.

Then, turn off the cold water valve, the hot water valve, and the inlet valve that supplies the water to the home. Then remove the purge port caps on the hot and cold ports (be careful not to disturb the rubber lining).

Next, you will need two washing machine hoses and a large bucket. One will attach to the hot outlet port valve, and the other will attach to the cold water inlet valve. Then open the purge ports to allow the water to flow into the bucket.

After allowing the water to drain, dump the water and fill the bucket with 4 gallons of white vinegar. White vinegar is a safe way to clean your water heater without causing damage to the system or your health. 

Next, you will need a submersible pump. Once the bucket is filled with vinegar, attach the hoses to the pump and submerge the pump the vinegar in the bucket. Then turn the pump on; this will pump the vinegar throughout the water heater system. Allow it to run for about 40 to 90 minutes, depending on how much buildup there is in your water heater. 

During the pumping process, remove the water heater faceplate and the air filter. Rinse out the air filter, dry it off, then replace it back on the water heater. Then screw the faceplate back on. 

After you are done pumping, please turn off the pump, unplug it, and remove it from the bucket. Empty the vinegar out of the bucket and place the bucket under the water heater. Then, remove the hose from the cold water inlet and screw the cold inlet cap back into place. 

Open the water valve and allow water to run through the system for a few minutes until the bucket gets full of water (about 4-5 gallons). Then close the valve. 

Next, unscrew the water filters, rinse them off, and then replace them back onto the water heater. 

Finally, attach the caps back onto the ports, turn on all the valves you closed off, turn on the gas supply or the circuit breaker, and then turn on the water heater to restore it back to full operation. 

Cleaning A Gas Water Heater

A gas tank water heater is the same as an electric water heater. The only difference is there is no circuit breaker to turn off, but instead, a gas supply valve you need to turn off. 

How to Clean Water Heater Parts

How To Clean Water Heater Thermocouple

1. Turn off the power to the water heater.
2. Loosen the thermocouple for cleaning. You may need a wrench or screwdrivers to help loosen it. 
3. Clean the sediment buildup and corrosion using sandpaper, steel wool, or an abrasive sponge to scrub off the buildup gently. Be sure to use a non-flammable cleaning product meant for the job. You could use vinegar for this too.
4. Use a lint-free cloth, such as a microfiber cloth, to remove excess particles
5. Reattach the thermocouple to the unit. Then turn the water heater back on.

How to Clean Water Heater Tank

1. Turn off the water heater and the power supply.
2. Close off all water valves, close the hot water purge port, and remove its cap.
3. Drain the water by opening the drain valves. Then close valves when done.
4. Attach 3 hoses to the system: one to the hot outlet valve, one to the pump inlet, and one to the cold inlet valve.
5. Fill a large bucket with a safe cleaning product specified for water heater tanks. Make sure it’s at least two gallons worth of solution mix. You could also use vinegar mix for this. You will want to place this under the pump hose. Then, place a second large bucket under the hot purge port hose.
6. Open the port valves, turn on the pump, and allow the solution to run through, emptying out into the second bucket. 
7. Repeat the pumping until the solution runs clear. Once clear, empty the bucket, fill it with water, and pump water through the system a few times to remove the vinegar. 
8. Clean up and reverse the setup process.

For more detail on each step, refer to the section below titled “How to Clean a Water Heater Using Vinegar”.

How To Clean the Water Heater Element

1. Turn off the water heater and the power supply. 
2. Turn off the cold water valve, and attach a hose to the drain valve. Open the drain valve and allow water to run out. Close the drain valve when done.
3. Access the panels to the heating element using a screwdriver. Then, use a screwdriver to remove the element and detach it from the wires.
4. Using a safe cleaning solution for the job (water + vinegar mix or sodium carbonate + water mix will work), gently scrub off the buildup using an abrasive sponge or a scoring pad. Wipe excess particles off using a microfiber cloth.
5. Reconnect the wires to the element, replace the element back on the water heater, then screw on the access panel.
6. Turn on the cold water valve and detach the hose. Then turn the water heater and the power supply back on to refill your water heater and make it operable. 

How Often Do You Need to Flush a Water Heater?

Flushing a water heater on a regular basis is a necessity. Periodic flushing can be of immense help when it comes to prolonging your water heater’s efficiency and lifespan.

It’s recommended to flush a water heater at least once a year to maintain its proper function; however, it’s also important to check the manufacturer’s instructions and use caution when working with the unit; in some cases, the frequency of cleaning and flushing may vary depending on the water hardness of the area, usage and the type of water heater.

The longer you wait to flush, the more sediment will buildup inside, making it harder to flush out later on. If neglected long enough, sediment buildup can cause such a significant amount of damage that you may need to replace the entire unit altogether.

To ensure this doesn’t happen, schedule your water heater flushing at least every 6 months. If you live in an area with really hard water, though, you will want to flush it more often (about every 3-4 months)

Signs For Needing to Flush the Water Heater

You shouldn’t need to know the signs for needing to flush your water heater as long as you are having it flushed periodically. However, if you can’t remember the last time you’ve flushed it, or if you know it’s been a while, here are some signs to watch out for:

Sediment buildup – This is the first sign to appear when you need your water heater flushed. You can visibly see this before any other signs occur, and you will continue to see it build up further if you do not take action to flush it out.

 Strange noises – If you hear strange noises that you are not familiar with coming from your water heater, it could be a sign that a part in the water heater is not working properly. The most common reason for noises and parts not working is sediment buildup blocking essential pathways. 

Strange noises can range from just about anywhere, from whistling to thumping to humming to clicking, among other sounds.

How to Clean a Water Heater with Vinegar

Using vinegar to clean a water heater can be a great option for getting rid of sediment buildup. It doesn’t change the water’s chemical composition nor cause any damage if remnants are left in the tank after cleaning. Here’s how you can use it to clean your water heater:

1. Step 1: Turn off the water heater and disconnect it from the power supply (allow time for the water to cool before moving further).
2. Step 2: Close the hot water valve and the cold water valve. Then close the hot water purge port, removing its cap (be careful not to disturb the rubber seal ring)
3. Step 3: Open the drain valves from both purge ports and drain out all of the water (be sure to wait for the water to cool down before this step). Once all of the water is out, close the drain valves.
4. Step 4: You will need 3 hoses for this step: One attached from the hot outlet port into a large bucket, another attached from the pump inlet into another separate, large bucket, and another attached from the pump to the cold water inlet port.
5. Step 5: In the bucket attached to the pump, fill the bucket with about ½ gallon of white vinegar mixed with 1 ½  gallons of hot water. Then, open the service port valves and turn on the pump to run the vinegar through your water heater. This will empty out into the other bucket.
6. Step 6: You will want to repeat this as often as necessary until the vinegar comes out clear in the second bucket. Once it runs clear, rinse the first bucket you poured vinegar into with water.
7. Step 7: Repeat step 5, but replace the 2 gallons of vinegar with 2 gallons of water. Do this cycle 5 times (with water), and most of the vinegar should be flushed out of your water heater. 
8. Step 8: Remove the hoses, and reverse steps 2 and 1 (starting with step 2, then 1) to restore your water heater to operating condition.

Why Cleaning and Flushing A Water Heater Is Important

Cleaning and flushing a water heater is important for several reasons:

1. Efficiency: Over time, sediment and minerals can accumulate in the bottom of the water heater tank, reducing the unit’s heating efficiency and potentially causing damage to the heating elements. Cleaning and flushing the water heater can remove this sediment and minerals, improving the unit’s efficiency and saving on energy costs.
2. Longevity: A dirty or clogged water heater can shorten the unit’s lifespan. Cleaning and flushing the water heater can help prevent damage to the internal components, ensuring that the unit will last for its full expected lifespan.
3. Safety: A buildup of sediment and minerals in the water heater tank can also be a potential fire hazard. Regularly cleaning and flushing the water heater can eliminate this hazard.
4. Quality of water: A dirty water heater can also affect the quality of the hot water that it provides; by cleaning and flushing the unit, the water will come out clear, and without sediment, also the hot water will have a better taste and odor.
5. Cost-effective: Regular maintenance, like cleaning and flushing, can help prevent more costly repairs or replacements in the long run.

Frequently Asked Questions

Final Thoughts

Cleaning your water heater is a great way to help extend the life of your water heater. It really doesn’t take that much time out of your day, especially given that you only need to clean it every few months or so.

By taking the time and care to ensure thorough maintenance and cleaning, you can expand your water heater’s efficiency and life, saving you money, time, and frustration in the long run.

So if you haven’t done so already, now is the time to get into the practice of cleaning your water heater regularly to get the most out of your hot water supply.