Quick Guide: Efficiently Drain Your Hot Water Heater

Draining your water heater once a year removes sediment from the tank that can cause it to work harder and cost more to use. The No. 1 cause of water heater failure is sediment buildup in the tank. Sometimes it makes a sizzling, crackling noise when the heating element fires up as it works harder to heat the water. This wastes energy and often requires earlier replacement. Flushing a water heater every year can remove a build-up of sediment from the bottom of the tank. That sediment can create a buildup on your water heater’s elements and make it harder for your water to get hot.
Regularly flushing out your hot water heater is an important task. Getting rid of the gunk and mineral deposits that accumulate will help your hot water heater run more efficiently as well as prolong its life, saving you money in the long run. Draining your hot water tank removes sediment buildup, helping your water heater perform more efficiently, which can save you money. If the tank isn’t annually drained, a hot water heater won’t last as long, and the water may heat more slowly.

Tools and Materials Needed

• Garden Hose: The distance from your water heater to where you’ll be draining will determine how long the hose will need to be.
• Pan: I suggest a stainless steel mixing bowl so that you can get a “clear” picture of what your water looks like.
• Old Towel: We’re working with water here and we’re probably going to get a little bit dirty. This is good to wipe your hands or clean up small drips or messes.
• Vice-Grips or Flathead Screwdriver: These may be handy if you don’t have a handle on the drain valve of your tank.
• Bucket: Useful for catching water when testing the pressure relief valve or draining small amounts.

Step-by-Step Guide to Draining Your Hot Water Heater

Step 1: Turn Off the Power or Gas

If you have a gas heater, turn off the gas. There should be a shutoff valve for the gas supply lines to your house, or your furnace may have a setting on the thermostat to cut off the gas supply to the tank. If you have an electric heater, go to the fuse box and turn off the breaker that controls the water heater. The water heater’s thermostat is usually located near the bottom of the heater. If you have a gas heater, turning off the thermostat may also turn off the pilot light. If so, don’t forget to relight the pilot when you’re finished draining the tank.

Step 2: Shut Off the Cold Water Supply

Look for a valve at the top of the tank, where the water supply pipe connects with the water heater unit. For many models, the valve will be part of the plumbing just before it reaches the water heater intake connection. While this is technically an optional step, it will reduce the risk of burns and any potential hot water damage. Shut off the cold water supply valve located at the top of your hot water heater by turning it clockwise until it stops.

Step 3: Let the Water Cool

If you try to drain scalding water, you’re likely to burn yourself. By waiting for the water to cool (about 30 minutes, but as many as 2 hours), you can more safely drain it. We suggest waiting for one or two hours to let the water cool down. This will avoid heat injuries.

Step 4: Check for Leaks

If you notice any dripping or standing water near your water heater, or any water near connected valves or pipes, you likely have a leak. A leak means higher water bills. It also means that your heater won’t run as efficiently as possible. If you do see a leak, you can often open and close the drain valve a few times to free up sediment blocking the drain. The extra pressure buildup will be released and the valve should function normally after the blockages are broken up. If the valve continues to leak or if you routinely see standing water in your drain pan, you should turn the cold water supply to the tank off immediately and call a plumber.

Step 5: Test the Temperature and Pressure Relief Valve

The T&P valve will be either high on the side or on the top of the water heater. First, make sure it works. If it isn’t functioning properly, pressure can build inside, causing your water heater to burst. To test the pressure relief valve, place a bucket underneath it to catch any water that may be discharged during testing. Lift the T&P lever part-way, allowing it to snap back into place. You should hear a gurgling noise as the valve sends some water to the drainpipe. If no water comes out or you don’t hear any gurgling, replace it immediately.

Step 6: Connect the Hose

Connect a strong garden hose to your water heater’s drain line, which looks like a spigot near the bottom of the tank. Use a strong hose. Cheap garden hoses can become soft when hot water runs through them, causing leaks. Run the hose to your basement drain or run it outside the house. If your hot water heater is located in your basement, you might need a pump to direct the water out through a basement window. The water drains out with the force of gravity, and it will not have sufficient pressure to travel any direction besides downward.

Step 7: Open Hot Water Faucets

Open a hot water faucet closest to the water heater, preferably on an upper floor, and the water heater drain valve. This prevents vacuums from forming. Don’t be alarmed if the water only trickles out. That’s normal. A vacuum may form within the pipes during the flushing process. You can stop this by turning on the hot water tap. Opening the hot water faucet allows to drain the water heater faster.

Step 8: Open the Drain Valve

Open the drain valve to release the tank’s water. You may be able to do this by hand, but sometimes a screwdriver is needed to assist in the process. The water will be hot, so use caution. If the valve is being particularly stubborn, you can usually dislodge it by spraying some WD-40 or a comparable lubricant onto the valve and letting it sit for a couple of minutes. The drain valve might require some gentle pressure and a little bit of wiggling in order to budge it, but you should never force the valve open or closed.

Step 9: Flush the Tank

Let all of the water completely drain from the tank. This can take anywhere from about 5-10 minutes, depending on the size of the tank. To flush the tank, turn the water back on by re-opening the water heater valve that we shut off in step 4. Monitor the color of the water coming out of your hose, and allow the water to run for as long as it takes for it to come out clean and clear. A good rule of thumb is to let the water run for about 5-7 minutes regardless to be absolutely sure that your water heater tank is as clean as possible.

Step 10: Refill the Tank

Close the drain valve and remove the hose. Turn on the cold water supply to refill the tank. Turn the knob counterclockwise to fill the tank with water. You’ll know that the tank’s full when you see a steady stream from the hot water tap you left open in one of your sinks. Leave the hot water faucets open until water flows steadily, then close them. Check for any leaks around the drain valve or other connections.

Step 11: Restore Power or Gas

If you have a gas water heater, turn the gas valve knob back on by turning it counterclockwise. If you have an electric water heater in your home, you can turn the power back on at the breaker panel. For gas heaters, relight the pilot light if necessary. Wait about 20 minutes for the water to heat up. Turn on a hot water spigot somewhere in your house to ensure hot water is coming out.

Troubleshooting Common Issues

Clogged Drain Valve

One possible reason for a hot water heater not draining is a clogged drain valve. Over time, sediment and debris can accumulate in the valve, obstructing the flow of water. To address this issue, it is recommended to flush your water heater regularly to remove any buildup. There is a few tricks for this. Hook up your drain hose. Shut off the water coming from the water heater but leave the cold water feed to the water heater on. Open the drain valve, the water pressure from the feed should stir up the sediment in the bottom and get the water moving.

Malfunctioning Heating Element

Another common cause of drainage problems is a malfunctioning heating element. If one or both elements fail to heat the water adequately, it can lead to sediment buildup and reduced efficiency. In such cases, it may be necessary to replace the faulty elements to restore proper functioning.

Incorrectly Installed Drain Line

An incorrectly installed or sized drain line can also contribute to poor drainage. If the pipe is too small or improperly sloped, it can impede the flow of water and cause backups. Professional inspection may be required to correct this issue.

Maintenance Tips for Longevity

• Regular Maintenance: Flushing your water heater at least once a year can help remove sediment and prevent clogs.
• Temperature Adjustment: Setting your water heater temperature between 120-140 degrees Fahrenheit can help reduce mineral buildup.
• Pressure Relief Valve Inspection: Checking your pressure relief valve annually ensures its proper functioning and prevents leaks.
• Professional Inspection: Engaging a licensed plumber for periodic inspections can identify potential issues early on and save you from costly repairs.
• Anode Rod Check: Check the anode rod every few years and replace it if necessary. Installing a Corro-Protec anode will reduce sediment buildup inside the tank and completely stop corrosion.

Comparison of Draining Methods

Best Product Recommendations

For efficient water heater maintenance, consider investing in high-quality tools and accessories. A reliable garden hose is essential for draining. We recommend the Flexzilla Garden Hose, known for its durability and flexibility, making it ideal for navigating tight spaces around your water heater. For sediment protection, the Corro-Protec Powered Anode Rod is a top choice, reducing corrosion and sediment buildup to extend your heater’s lifespan.

Frequently Asked Questions

How often should I drain my hot water heater?

Draining your water heater once a year is generally recommended. If you live in an area with hard water, you may need to do it every six months to prevent excessive sediment buildup.

Can I drain my water heater without turning off the power?

No, it’s unsafe to drain your water heater without turning off the power or gas. For electric heaters, this risks damaging the heating elements if they operate without water. For gas heaters, it could cause overheating or other hazards.

What should I do if the drain valve is stuck?

If the drain valve is stuck, apply a lubricant like WD-40 and let it sit for a few minutes. Gently wiggle the valve to loosen it. If it remains stuck, consult a professional plumber to avoid damaging the valve.

Is it normal for sediment to come out during draining?

Yes, seeing sediment during draining is normal, especially if the heater hasn’t been flushed recently. Continue flushing until the water runs clear to ensure all sediment is removed.

When should I call a professional?

Call a professional if you encounter persistent leaks, a non-functioning pressure relief valve, or if the water heater hasn’t been flushed in over three years. Complex issues like a clogged drain line or faulty heating elements also require expert attention.

Additional Resources

For more information on water heater maintenance, check out these authoritative resources:

• This Old House: Water Heater Maintenance Tips
• U.S. Department of Energy: Water Heating Guide
• Family Handyman: DIY Water Heater Flush