Draining a Water Heater

Over time our water heaters build up sediment inside them from all the water passing through. This sediment can cause problems in your water heater making it less efficient. The sediment may also cause lime buildup which can result in water heater elements burning out and tank corrosion. It is usually a good idea to drain your water heater at least once a year, to remove any sediment in the tank. Here is a step by step procedure of how to safely drain your water heater.

Step 1: Turn off the power

For electric water heaters, turn off the water heater elements by switching the breaker at the main circuit panel. This is usually a 30 amp or 40 amp breaker. For gas water heaters, turn the thermostat to pilot. That is the top red knob on the picture to the right. If you turn the knob to off, then you will have to re-light the pilot once you are finished draining your tank.

Electric Panel

Gas Valve

Step 2: Turn of the water

The next step is to turn off the water heaters water supply. Most water heaters have a shutoff valve on top of the tank, this is a valve on the pipe entering the water heater. If you can't find it or it is difficult to turn, you can also shut off the water to the entire house instead.

Water heater Shutoff

House Shutoff

Step 3: Connect drain hose

Connect a garden hose to the drain valve located at the bottom of the water heater. Place the other end of the garden hose into a drain nearby, or outside on the ground.

Step 4: Open the drain valve

Open the drain once the hose is attached. If you have a plastic white drain valve like the one in the picture to the right, then you turn it counter clockwise to open it. Turn it completely around once. This should get the water flowing out of the tank, slowly. Be careful, this type of drain valve is not very sturdy.

Drain Valve

Step 5: Let it drain completely

Turn on a hot water faucet somewhere in the house to prevent a vacuum from forming within the lines. When you do this you will hear air rushing into the faucet and the water heater will begin draining faster. Check the water being drained from the tanks color. At first it will likely be brown and dirty. After a while it should turn clear.

Step 6: Refilling the tank

When it has turned clear close the drain valve, remove your hose and open up the water heater shut off valve to let water back into the tank. Leave the faucet (vacuum relief) open so that all the air that entered the tank is pushed back out of the tank. Once water is coming out of the faucet and not air, you can turn off the faucet. Now turn the electric or gas back on and your done.