How to Drain Your Water Heater: A Step-by-Step Guide 

Tank water heaters are a dependable way to provide a fast supply of hot water for your home. The presence of a storage tank ensures some hot water is always available. But over time, foreign substances may build up inside the storage tank. This could be sediment or mineral buildup arriving from the main water line or a flaw in the pipes. Whatever the source is, this buildup could reduce the efficiency of water heaters. In severe cases it can clog up drainage and might even lead to premature failure.

Thankfully, draining your water heater and clearing out sediment buildup is a relatively simple task. A certified plumber in the U.S. can handle the process, but you can also drain the tank on your own if you know what you’re doing. Either way, draining the tank now can help reduce the risk you’ll need premature water heater replacement.

Before You Begin…

Before you start draining the tank, you’ll need to shut off the cold water supply. The supply valve connects your water heater with the main water line. Unless you have access to a well (and you might need to drain the tank more frequently if you do), the water main delivers all the potable water your home uses. Keeping the valve closed will stop more water from flowing into the tank, allowing you to completely empty it.

You’ll also want to have a rubber hose, like one you would use for yard work. The hose allows you to safely drain the water heater tank without spilling water all over your garage, utility closet, attic or wherever the water heater is stored. Make sure you place the other end of the hose far away from your home to prevent the water from flooding back inside.

Finally, a screwdriver will help you loosen tight screws or valves. You shouldn’t need any more tools than this unless you stumble upon a problem with the water heater or nearby piping. At that point, it might be best to hire a certified plumber in the U.S..

Step 1: Shut Off the Water Heater

After you’ve shut off the water supply, you can shut off the water heater itself. This will be on the thermostat for natural gas water heaters or via a breaker switch for electric models. The pilot setting on gas water heaters can remain on during flushing, but electric models need to be completely off. This is because of the heating elements electric water heaters use, which remain submerged. In an empty tank, they may quickly overheat. You should also find the model’s manual, as some water heaters have to be completely full before the heating elements are turned on.

Even after you’ve shut off the water heater, you’ll have to wait for the water stored in the tank to cool down. It can be hours before the water cools to a safe temperature, so it is usually best to leave the remaining steps for the following day.

Step 2: Secure the Hose to the Water Heater’s Drain Valve

Tank water heaters are designed with a drain valve you can use to empty the storage tank. Once you’re sure the water supply is disconnected and the water heater itself is off, locate the drain valve. Some models might have it covered up. Make sure the hose is firmly attached to prevent spilling hot water near you and the water heater.

Step 3: Open a Faucet or Other Hot Water Tap

Your home’s plumbing takes advantage of pressure inside the piping to maintain a consistent flow of water from the main water line to the rest of the house. This pressure will have to be relieved before the hot water can actually flow from the tank. By heading to the nearest faucet or spigot, you’ll release the pressure inside the piping. All you have to do is open the hot water tap to relieve the pressure before returning to the water heater.

Step 4: Release the Drain Valve

Don’t forget that this water may still have some residual heat. Open the drain valve and allow all the water to drain from the tank. This should carry sediment buildup out of the tank and away from your home. But some buildup might be stuck to the inside of the tank. Turning the cold water supply back on will help flush stubborn minerals and other substances from the tank.

Repeat this step until the water appears clear of sediment or minerals. If the drain isn’t working because of a clog, a trained plumber is likely required.

Step 5: Re-Shut the Valve Before Refilling the Water Heater

If everything proceeds normally, you should be able to clear out most excess sediment hiding inside your water heater. Close the drain valve, detach the hose and open the water supply to get things working again. As the water heater tank starts to fill, return to the hot water tap you opened. Once cold water starts to flow, you know the pressure is back at appropriate levels.

At this point, you can open the gas valve or flip the breaker switch back on. Like we mentioned earlier, don’t forget that certain models may need to be entirely full before the water can be safely heated. Make sure you review your manufacturer’s instructions before starting the process.

Keep Your Water Heater Sediment-Free for Best Results

Tank water heaters continue to be a great option for supplying your hot water needs. Draining the tank every 1-2 years will help clear out sediment buildup and keep things running at peak efficiency. If you think your water heater is past the point of efficient heating, consider looking for water heater replacement in the U.S. from a technician you trust.