How to Flush a Water Heater in Texas

Schedule a FREE Estimate Today

For Immediate
Service Call


Fast Service

We understand that when you have a plumbing issue you need prompt service.

Schedule a service

Affordable Pricing

We are committed to providing effective plumbing solutions at affordable prices.

Call for your free estimate

How to Flush a Water Heater in Texas

Flushing a water heater is an important aspect of home maintenance, particularly in Texas where hard water can accelerate sediment buildup. This guide will walk you through the process step-by-step.

Key Takeaways

  • Preparation: Before you flush your water heater, look for signs of sediment buildup, such as reduced hot water capacity or strange noises. Make sure you have the right tools too, including a garden hose and access to your home’s breaker box or gas supply.
  • Safety First: Always prioritize safety. We can’t stress this enough. The very first thing you need to do is turn off the power or gas supply to your water heater to prevent any accidents when handling hot water and electrical or gas components.
  • Professional Assistance: Sometimes, there is only so much you can do. If you encounter complex issues or extensive sediment buildup, don’t hesitate to contact us.

How to Know that Your Water Heater Needs to Be Flushed

A problematic drain valve at the bottom of a water heater.

If you’re experiencing less hot water, strange noises, or discolored water, it might be time to flush your water heater. These signals often indicate sediment buildup that can affect the efficiency and life span of your water heater. A water heater is a big enough expense that you want to get as much out of it as you can. So let’s talk about what you should do to keep it running smoothly.

Safety Considerations

Always prioritize safety. Turn off the power supply to an electric water heater at your home’s breaker box or shut off the gas supply if you have a gas water heater. This prevents accidents and injuries during the flushing process. Do NOT attempt a flush until you have turned off the power or gas.

Instructions for Flushing a Water Heater

turn off water heater

1. Turn Off the Water Heater

  • Gas Water Heaters: Locate the gas pipe that leads to the heater. Turn off the gas supply using the gas valve. Alternatively, you can set the pilot light to “off” or “pilot” position. This stops the heater from heating while allowing the pilot light to stay lit, which can be useful if you are uncomfortable relighting it.
  • Electric Water Heaters: Locate your home’s breaker box. Identify the breaker switch for the water heater and flip it to the “off” position. This will cut off the electrical power to the heater before you start the flush.

2. Turn Off the Cold-Water Supply

Find the cold-water valve connected to your water heater. This is usually a lever or a knob located at the top of the tank. Turn it to the “off” position to stop cold water from entering the heater. This is necessary for a safe and effective flush.

3. Allow the Water to Cool

Depending on the size of your hot water tank, the cooling process could take a few hours. Just be patient. You need to wait since the water inside can be extremely hot and pose a risk of scalding during the draining process.

4. Locate the Drain Valve and Connect It to a Hose

connect hose to the bottom of water heater

The drain valve is typically located at the bottom of the tank. Attach a garden hose to this valve. Ensure that the other end of the hose is directed toward a drainage area, like a floor drain or even outside. This could also be a good opportunity to inspect the condition of the existing drain valve for any leaks or damage.

5. Turn on a Hot Water Faucet

hot water faucet

Turn on a hot water faucet in your house (preferably on the ground floor or the same level as the water heater). Doing so will prevent a vacuum from forming in the lines and allow the water to drain more easily from the tank.

6. Open the Drain Valve and Allow the Tank to Drain

Slowly open the drain valve and allow the water to flow out through the hose. Initially, the water may appear cloudy or slightly colored due to the sediment. It’s important to let the tank drain completely. Again, just be patient. It might take some time depending on the size of your hot water tank.

7. Flush the Tank

After the tank has drained, turn on the cold-water spigot that leads to the tank for a brief period to flush out any remaining sediment. You might need to do this step several times until the water runs clear from the hose. This step ensures that most of the gunk and mineral deposits are removed from the tank.

8. Wrap Up the Draining Process and Allow the Tank to Refill

Once the water runs clear, close the drain valve and remove the hose. Turn on the cold-water valve to allow the tank to refill. Ensure there are no leaks around the drain valve.

Once the tank is full (you will hear water stop flowing), turn the power back on at the breaker box for electric water heaters, or turn on the gas supply and relight the pilot light for gas models. Finally, check the hot water heater’s thermostat to make sure it’s set at the desired temperature.

When It’s a Good Idea to Call a Professional

While regularly flushing your water heater extends its life and improves efficiency, certain situations warrant professional intervention.

For instance, extensive sediment buildup, issues with the pressure relief valve, or complications with the gas pipe or electrical connections all require professional help. City Base Plumbing, with our expertise in dealing with both electric and gas water heaters, is an excellent resource for residents in Texas who face more complex issues with their water heaters.


Add flushing your water heater to your list of household chores. Not only does it extend the life of your water heater, but it also ensures you always have access to hot water. Not to mention, properly maintaining your water heater can save you time and money. Contact City Base Plumbing for more information.

Looking for a San Antonio plumber you can trust?

Schedule a call now!