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

Tank water heaters are a reliable way to provide a fast supply of hot water for your home. The inclusion of a storage tank ensures some hot water is always available. But over time, foreign substances may build up within the storage tank. This may be sediment or mineral buildup getting in from the main water line or an opening in the pipes. Whatever the source is, this buildup can lower the efficiency of water heaters. In severe cases it can plug up drainage and might even lead to premature failure.

Fortunately, draining your water heater and removing sediment buildup is a relatively simple task. An experienced plumber in the U.S. can handle the process, but you can also drain the tank yourself 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 should 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 may need to drain the tank more often if you do), the water main provides all the potable water your home uses. Keeping the valve shut will stop more water from reaching 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 in your garage, utility closet, attic or wherever the water heater is kept. Make sure you put the other end of the hose far away from your home to stop the water from flooding back inside.

Finally, a screwdriver can help you loosen stubborn screws or valves. You shouldn’t need any more tools than this unless you stumble upon a problem with the water heater or adjacent piping. At that point, it may be best to call 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 due to the heating elements electric water heaters have, which remain submerged. In an empty tank, they can quickly overheat. You should also review the model’s manual, as some water heaters have to be completely full before the heating elements are reactivated.

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 reaches a safe temperature, so it is usually best to leave the remaining steps for the following day.

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

Tank water heaters have a drain valve you can use to empty the storage tank. Once you’re confident the water supply is disconnected and the water heater itself is off, locate the drain valve. Some models will have it covered up. Make sure the hose is secure 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 uses pressure within the piping to maintain a consistent flow of water from the main water line to the rest of the house. This pressure needs to be relieved before the hot water can actually exit the tank. By heading to the closest faucet or spigot, you’ll alleviate 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

Keep in mind that this water could still have some residual heat. Open the drain valve and allow all the water to drain from the tank. This should pull 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.

Keep repeating this step until the water looks free of sediment or minerals. If the drain isn’t working because of an obstruction, a trained plumber is likely required.

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

If everything proceeds like it’s supposed to, you should be able to remove most excess sediment stuck inside your water heater. Close the drain valve, detach the hose and open the water supply to get things flowing again. As the water heater tank begins to fill, return to the hot water tap you opened. Once cold water starts to flow, you know the pressure is back where it needs to be.

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

Keep Your Water Heater Sediment-Free for Best Results

Tank water heaters are still 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.