How to Drain a Water Heater – DIY 8 Easy Steps Guide

How to drain a water heater

Water heaters come with a sizeable insulated tank to ensure constant water availability. However, although these appliances are supposed to heat the water and keep it hot for long, their energy efficiency declines with time, especially when not cleaned often. And this is mainly due to the build-up of sediment in the tank. Most manufacturers encourage users to maintain their water heater tanks by draining them regularly for optimal performance. However, most people don’t know how to drain a water heater.

Knowing how to drain a water heater is critical if you want your machine to serve you for long. Regularly draining your water heater can enhance its performance and increase its lifespan since it prevents sediment accumulation. By draining the hot water heater each year, you will be able to save money by having a much more energy-efficient water heater.

If you want to do it yourself, this step-by-step guide on how to drain a water heater is perfect for you.


If you’ve never flushed your water heater on your own before, it’s crucial to be cognizant of what might happen in the process. If you are not comfortable with How to Drain a Water Heater by yourself, you should contact a professional.

If the Water Heater Drain Valve How to Drain a Water Heater - DIY 8 Easy Steps Guide 1 is too old, it may not be possible to reuse it, forcing you to look for a quick fix. In this case, you could put a cap over it. Alternatively, you could replace it. You could also upgrade it, especially if it’s a plastic one.

1. Stop the Water Heater

Your water heater shouldn’t be running when you start this process. Turn the heater off regardless of whether it’s a gas or electric water heater.

For a gas water heater, simply shut off the gas.

If it’s an electric heater, turn off the power (circuit breaker).

The water will only cool down when the power is off. Draining the water heater while the machine runs may get the water to dangerous heat levels, damaging the heating elements.

2. Stop Water Supply

Turn off the water supply by turning off the cold water supply valve. You could incur huge bills if you let the water to continue running at this stage.  

3. Let the Water Cool Down

It’s advisable to give the water in the tank enough time to cool. This can take around one to two hours. 

4. Fasten the Pipe to the Drain Valve

Identify where you want to drain your water and connect the drain valve to a standard garden hose. Thread the hose tightly to avoid leaks. You can drain the water into a container, driveway or the sewer line. Easiest way is to drain it directly in the floor drain.

5. Open the Faucet

A vacuum may form within the pipes during the flushing process. You can stop this by turning on the faucets. Don’t get worried when you notice the water coming out is little. That’s because there’s no supply.

6. Turn On the Drain Valve

Empty the tank by opening the drain valve. You can use a screwdriver to operate the valve. Avoid any leaks or overflows as they may flood the room. Let the tank drain the dirt.

7. Flush the Tank

If the water draining out isn’t clean, let in more cold water to stir up the remaining dirt. Keep the water flowing in and draining the tank until there’s no more sediment left.

8. Refill the Water Heater

Make sure the close the drain valve. Remove the hose from the drain valve and then turn on the heater. Refill the water heater with clean water. Check if there are any water leaks and correct the situation if you find any.  

Test your hot water tank. Your water should heat again in several minutes. Always go through your manufacturer’s directions before draining a water heater on your own.

When to Drain Your Water Heater

Lack of proper maintenance may have adverse effects on the lifespan of even the most valuable water heater. The heat produced by these machines is responsible for the accumulation of dirt in the tank’s base. The performance of your heating machine may deteriorate if you fail to clean it to remove the sediments. Plus, a poorly serviced water heater will consume more power than a clean one. Now that you know how to drain a water heater, you should do it every year.

Here are indicators it’s time to flush your water heater.

1. Hot Water Not Lasting Long                         

If you don’t clean your water heater for a long time, the excess minerals and sediment in the water may occupy a significant part of the tank. The presence of these natural minerals may reduce the space available for water in the tank, causing it to drain quite fast. The only way to reclaim the lost space is to flush the water heater.

 If you have no hot water because of sediment buildup, you should think about installing a powered anode rod since it will reduce limescale accumulation inside the tank.

2. Changing Water Temperature   

If you’ve been using your water heater for some time, you should be quick to notice abnormalities. The water heater may fail to function properly because of the presence of dirt. There could be a change in temperature when using the water heater. Make sure the problem is not only that the hot water temperature needs to be adjusted.

The dirt may also block pipes when it gets into the heat-out tube. The blocking of the pipe may lead to a change in water pressure. Flushing the water heater could be your only solution

3. Water Heats Up Slowly

When sediment accumulates, it forms a layer that comes in between the water and the heating surface. Consequently, it takes longer to heat the water. If your water is not heating fast as it used to, it could be because there’s too much dirt in the water heater. However, before embarking on this process, confirm if the temperature settings are correct.

4. Rumbling Noise

Popping sounds when running a water heater could be because of sediment accumulation. When you hear such noises when running your water heater, it could be the right time to clean it.

5. Bad Odor

If you don’t clean your water heater regularly, you may notice deterioration in the water quality. The water may change color and have a strange smell. If you notice a rusty look, it could be the right time to flush the water heater.

Another kind of smell that we see very often in water heater is sulfur smell. If you are experiencing that smell, draining the water heater won’t make any difference. The best thing you could do is install a powered anode. If you want to learn more about how to solve that sulfur smell, click here.

Professional Water Heater Draining Service

If you’re a DIY enthusiast, you can try these steps if your water heater is not functioning properly. However, not all people may find draining a water heater on their own easy. Plus, a lot could go wrong during the DIY exercise. For instance, the valves or heating elements may get damaged, leading to expensive losses.

A professional plumbing company can do everything for you at a reasonable price. A plumber can do all the required water heater maintenance to ensure your water heater is in good shape.

This blog post ”How to drain a water heater” is made available by Corro-Protec, for educational purposes only to give the reader general information and a general understanding on the specific subject above. The blog should not be used as a substitute for a licensed plumbing professional in your state or region. Check with city and state laws before performing any household project.


  1. Avatar Jack Wilson on August 18, 2020 at 2:48 am

    Hey, one thing I must say this is such an informative blog and I am looking for it for a couple of days. Regular draining the hot water each year will save money by having a much more energy-efficient water heater. Thanks for guiding step by step!

  2. Avatar Andrew Pires on September 17, 2020 at 5:25 pm

    Does your anode stop air build up in the hot water lines due to the water reacting with a mag anode (My current situation)

    • Avatar Corro-Protec on September 18, 2020 at 7:55 am

      Hello Andrew,
      Yes it will stop that reaction.

  3. Avatar Justin Heck on January 6, 2021 at 3:38 pm

    I drained a water heater at my mothers house that was over 30 years old and had never been cleaned. it was over 1/3 of the way full of black goop. The sediment had built up so much i ended up replacing the Unit. Proper Maintenance would have prevented this.

  4. Avatar Brenda on April 23, 2021 at 9:32 am

    Are you supposed to turn off the house water supply or just the cold water to the water heater?

    • Avatar Corro-Protec on May 5, 2021 at 7:06 am

      Brenda, in order to drain the tank you can turn off the cold water to the water heater only.

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