When you're having problems with an electric water heater and trying to troubleshoot the issue or repair it, you may need to drain the tank. A partial draining can also be preventative maintenance to keep sediment from building up. This is typically recommended every three to six months.
No matter the reason why you need to drain your electric water heater, be sure to follow these steps to do the job properly.
Before You Begin
Before you do anything else, you must first turn off the power to the water heater. This is done at the electrical panel by disabling the circuit breaker or fuse powering the water heater.
Next, turn off the water supply to the water heater. You should find a water shutoff valve at or near the cold water inlet pipe at the top of the tank. Turn the valve clockwise to shut it off. If you cannot find a local shutoff valve, turn off the water supply to the house at the main valve.
Equipment / Tools
- Garden hose
- Flathead screwdriver
- Rubber work gloves
Locate and Prepare the Drain
The drain cock at the bottom of the water heater tank is a silver, brass-colored, or plastic valve with a threaded end. This is where water comes out of the water heater. You need somewhere for the water to go as you drain the tank.
You can either place a bucket under the drain valve or attach a garden hose to the threaded end of the valve. Run the garden hose to a floor drain if you use that option.
Open the Pressure Release Valve
You will then need to locate the water heater's temperature and pressure (T&P) valve so you can relieve pressure from the tank. It is either on the side or the top of the water heater. Look for a valve that has a tube leading downward.
Flip the lever on the T&P valve into an up position to open it.
Let the Water Cool
Though you can drain a water heater while the water is hot, best safety practices suggest you would let the water cool down to avoid risks of scalding. You can do this by waiting a few hours.
Drain the Tank
With all safety precautions taken, it is time to drain water from the tank. Some drain valves have a handle. Others have a short handleless stem with a slot for a flathead screwdriver.
Turn the valve counter-clockwise to release a few gallons of water into the bucket or hose for a partial flush. If you are doing a complete drain and are using a hose, let the tank drain until empty.
When using a bucket for a full flush, you should use rubber gloves to avoid getting scalded. Fill the bucket and open and close the valve as many times as needed to empty the tank. Make sure to only partially fill the bucket if you need to tip it to get it out from under the valve spout.
Close the Valve
Once the draining is complete, close the T&P valve by flipping the lever down and close the drain valve by turning it clockwise. Empty the bucket or remove the hose.
Restore Power and Water
With the tank drained, you can perform any maintenance required. When the repair is complete, or if this was just a maintenance flush, turn the power and water supply to the water heater back on.