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.

Instructions

1. Shut off the electricity

Switch the two house circuit breakers dedicated for the water heater to OFF.

Wear work gloves to protect your hands.

2. 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.

3. Remove the drain valve

Remove the garden hose from the drain valve.

Unthread the drain valve from the tank.

4. 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.

5. 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.

Warning: Don't restore power to the water heater until the tank is full of water.

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.

6. Restore power

Flip the house circuit breakers to the ON position.