July 01, 2015

How to replace a water heater drain valve

This DIY repair guide explains how to replace the drain valve in a water heater. The drain valve at the bottom of the tank is threaded so you can attach a garden hose and drain the tank to flush sediment from the water heater. If the drain valve leaks, replace it with the manufacturer-approved water heater part.

Use this procedure to replace the drain valve in Kenmore, A. O. Smith, State, Rheem, Reliance and Whirlpool water heaters.

Quick links

Video

Instructions

Tools required

Work gloves

Channel-lock pliers

Pipe thread-sealing tape

Repair difficulty

Time required

30 minutes or less

How to replace a water heater drain valve repair guide video.

Replacing a water heater drain valve video.

Instructions

01.
Shut off the electricity
Switch the two house circuit breakers dedicated for the water heater to OFF.
Wear work gloves to protect your hands.

PHOTO: Switch the water heater circuit breakers off.
02.
Drain the water heater
Turn off the cold water supply to the water heater.
Attach a garden hose to the drain valve located at the bottom of the unit and run the garden hose outside.
Open a hot water faucet in the house or flip the relief valve open on the water heater.
Open the drain valve and allow the tank to drain until empty.
PHOTO: Turn off the cold water supply.
PHOTO: Attach the garden hose the water heater heater drain valve.
PHOTO: Flip the pressure relief valve to the open position.
PHOTO: Open the drain valve.
03.
Remove the drain valve
Remove the garden hose from the drain valve.
Unthread the drain valve from the tank.

PHOTO: Remove the garden hose.
PHOTO: Remove the drain valve.
04.
Install the new drain valve
Wrap some thread-sealing tape around the threads of the new drain valve.
Install the new drain valve and tighten firmly.

Tip: Clean sediment from the opening before installing the new drain valve.
PHOTO: Apply thread sealing tape to the drain valve.
PHOTO: Install the new drain valve.
05.
Fill the tank with water
Turn the cold water supply on to the water heater and allow the tank to fill with water. Once you see water coming out of the hot water faucet, turn the hot water faucet off.

Tip: Once the water heater is full of water, water will begin to flow from the hot water faucet that you left open when draining the tank.
Warning: Don't restore power to the water heater until the tank is full of water.
PHOTO: Turn on the cold water supply.
06.
Restore power
Flip the house circuit breakers to the ON position.
PHOTO: Flip the circuit breakers to the On position.

Warning: Undertaking repairs or maintenance to appliances or power equipment can be hazardous. Should you choose to undertake repairs or maintenance, you are assuming the risk of injury to your person or property. In an effort to reduce the risk, use the proper tools and safety equipment noted in the applicable guide and follow all instructions. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs or maintenance, however, should only be performed by a qualified technician.