How Long Does It Take to Drain a Water Heater? The Ultimate Guide

Water heaters are an essential component of modern households. They help to heat cold water and make it more comfortable for use in showers, baths, washing machines, dishwashers, etc.

Over time, water heaters can accumulate mineral buildup and sediment that can affect their performance. This is when draining is needed. Draining a water heater involves emptying out the tank and flushing it with fresh water so all sediment is removed and the unit runs efficiently again.

So, how long does it take to drain a water heater? Typically it takes between 15 and 30 minutes, but it depends on factors like the type of water heater, its capacity, etc.

Whether you’re planning routine maintenance or replacing your unit, this article will provide you with all the information you need to know about how long it takes to drain a water heater. From determining the draining time to following the necessary steps, you’ll be able to keep your hot water supply running smoothly.

What Is a Water Heater?

Before we get into the details of how long it takes to drain a water heater, let’s look at the type of system you’ll be dealing with.

A water heater is a device that heats and stores hot water for residential or commercial purposes. It’s usually powered by electricity or gas and comes in several sizes to fit different needs.

Types of Water Heaters

Water heater

There are various types of water heaters, each with its own set of features and characteristics. Here are some of the most common:

Tankless Water Heater

Tankless water heaters are the latest trend in hot water systems, thanks to their numerous benefits. They don’t require a storage tank and rely on instant heating to provide hot water on demand.

Tankless water heaters are energy sufficient, last longer, and are quite easy to fix – however, they can be more expensive to buy.

Traditional Water Heater

A traditional water heater uses a storage tank to store hot water. It heats water in a tank and stores it until needed for use. The tank is typically made of metal and is insulated to retain heat.

A traditional water heater uses either an electric heating element or a gas burner to heat the water in the tank. The heating element or burner is controlled by a thermostat that maintains the water temperature at a set level.

When hot water is needed, it’s drawn from the top of the tank, and cold water enters the bottom of the tank to be heated.

Traditional water heaters are commonly used in homes and are widely available in various sizes and capacities to meet the hot water needs of different households. They are less expensive, but they are not as strong as tankless water heaters.

Solar Water Heater

A solar water heater is a system that uses solar energy to heat water. It consists of a solar collector, usually located on the lid, that absorbs sunlight and converts it into heat which is then transferred to a storage tank.

There are two types of solar water heaters: Active and passive. Active solar water heaters use pumps and controllers to circulate water through the solar collector and into the storage tank. Passive solar water heaters rely on gravity and the natural flow of water to circulate water through the collector and into the storage tank.

Heat Pump Water Heater

This type of water heater draws heat from the surrounding air and transfers it to the water in the tank. It is usually powered by electricity, but can also be powered by natural gas or propane. Heat pump water heaters are more energy efficient than traditional electric water heaters because they use less electricity to generate the same amount of hot water.

How Long Does it Take to Drain a Water Heater?

Man checking water heater

Now that you have a better understanding of the type of system, let’s take a look into how long it takes to drain a water heater.

Generally, draining a water heater should not take more than 15 to 30 minutes because the amount of water in the tank is usually not very large. However, the time it takes can be affected by several factors, including:

  • Size of the water heater
  • Water pressure
  • The location of the drain valve
  • Sediment buildup in the tank.

The process of preparing for the draining can take some time. It is always best to make sure that you have all the necessary tools, such as:

  • Bucket
  • Adjustable wrench
  • Garden hose
  • Flat-head screwdriver
  • Materials
  • Drain valve (optional)
  • Threaded hose cap (optional)

Steps to Drain a Water Heater

Now that you know how long it takes to drain a water heater, let’s look at the steps required to do so:

Step 1: Quick Flush

Before you drain your water heater, it’s important to flush out your water heater tank. This will help remove any debris or sediment stuck on the inside and improve its performance and efficiency.

To do this quick flush, simply open the drain valve at the base of your water heater, connect your hose to avoid messing up your home, and let the tank flush out for a few minutes. You can repeat this task until the water in the hose runs clear.

Step 2: Turn Off the Power Supply

If your water heater runs on electricity, turn off all power sources to ensure safety while working with the unit.

Step 3: Shut Off the Water Supply

The next step is to shut off the water supply valve, which is usually located at the top of the tank.

Step 4: Connect a Hose to the Drain Valve

Find the drain valve and attach a garden hose to it. If the drain valve is positioned at a lower level, you may need to get a threaded hose cap and attach it to the end of the garden hose.

Step 5: Open Drain Valve

Slowly open the valve. Make sure there is a bucket or container placed underneath to catch the released water or use a long hose to lead the water out.

Step 6: Get Rid of Sediment

Flush out any sediment that may have been collected in the tank. Fill the tank with clean water and wait for a couple of minutes before you drain it again. Or once you have drained all the water in the water heater, use a flat-head screwdriver or a brush to get rid of the sediment stuck at the bottom of the tank.

Make sure that you are wearing gloves and eye protection during this process.

Step 7: Close Drain Valve

Once all the water has been drained from the tank, close the valve by turning it clockwise with an adjustable wrench.

8. Turn on the Water Supply

Turn the water supply back on and let it run for a few minutes to refill your tank.

Draining a water heater is not too difficult and shouldn’t take longer than 15-30 minutes. Make sure that you have all the right tools and supplies to get the job done with ease.


Draining a water heater is important to improve its performance and efficiency. By following the above steps, you can easily drain your water heater in 15-30 minutes. Just make sure you have all the necessary tools and supplies before getting started!

We hope that this article has helped you understand the process, as well as factors that can affect draining time.

With years of experience under his belt, Adam decided to put his water heater knowledge to work. By providing high-quality content and expert guides, Adam hopes to help anyone looking for expert water heater advice.