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

Tank water heaters are a reliable way to secure 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 inside the storage tank. This can be sediment or mineral buildup originating from the main water line or an opening in the pipes. Whatever the culprit is, this buildup can negatively impact the efficiency of water heaters. In severe cases it can plug up drainage and might even cause premature failure. 

Thankfully, draining your water heater and clearing out 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. Whatever you choose, draining the tank now can help minimize 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 may need to drain the tank more often if you do), the water main delivers all the potable water your home uses. Keeping the valve closed will stop more water from reaching the tank, allowing you to completely empty it. 

You’ll also want to get a rubber hose, like one you can 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 kept. Make sure you leave the other end of the hose far away from your home to stop the water from flooding back inside. 

Finally, a screwdriver will 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 with a breaker switch for electric models. The pilot setting on gas water heaters can continue to stay on during flushing, but electric models must be completely off. This is because of the heating elements electric water heaters use, which remain submerged. In a drained tank, they can quickly overheat. You should also find the model’s manual, as some water heaters need to be completely full before the heating elements are turned on. 

Even after you’ve shut off the water heater, you’ll need to wait for the water stored in the tank to cool down. It could be hours before the water reaches a safe temperature, so it is often 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 possess a drain valve you can use to empty the storage tank. Once you’re certain the water supply is disconnected and the water heater itself is off, go ahead and find the drain valve. Some models may 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 uses pressure inside 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 flow from 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 

Remember that this water might 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 may be stuck to the inside of the tank. Turning the cold water supply back on will help wash away stubborn minerals and other substances from the tank. 

Repeat this step until the water looks clear 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 normally, you should be able to clear out most excess sediment stuck inside your water heater. Retighten the drain valve, detach the hose and open the water supply to get things flowing again. As the water heater tank begins to fill, head back 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 before, don’t forget that certain models might need to be completely full before the water can be safely heated. Make sure you look through 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.