July 1, 2015

How to replace a water heater drain valve

By Lyle Weischwill
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 replacement part.

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

Quick links
Tools required
Work gloves
Channel-lock pliers
Pipe thread-sealing tape
Repair difficulty
Time required
30 minutes or less
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

  1. 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.

    Switch the water heater circuit breakers off.

    Switch the water heater circuit breakers off.

  2. 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.

    Turn off the cold water supply.

    Turn off the cold water supply.

    Attach the garden hose the water heater heater drain valve.

    Attach the garden hose the water heater heater drain valve.

    Flip the pressure relief valve to the open position.

    Flip the pressure relief valve to the open position.

    Open the drain valve.

    Open the drain valve.

  3. 03.

    Remove the drain valve

    Remove the garden hose from the drain valve.

    Unthread the drain valve from the tank.

    Remove the garden hose.

    Remove the garden hose.

    Remove the drain valve.

    Remove the drain valve.

  4. 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.
    Apply thread sealing tape to the drain valve.

    Apply thread sealing tape to the drain valve.

    Install the new drain valve.

    Install the new drain valve.

  5. 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.
    Turn on the cold water supply.

    Turn on the cold water supply.

  6. 06.

    Restore power

    Flip the house circuit breakers to the ON position.

    Flip the circuit breakers to the On position.

    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.

Symptoms common to all water heaters

Choose a symptom to see related water heater repairs.

Main causes: broken heating element, thermostat failure, excessive tank sediment, tank size too small, burner valve assembly failure
Main causes: thermostats need adjustment, water heater capacity too low, bad heating element, thermostat failure, excessive tank sediment
Main causes: thermostat temperature set too high, thermostats need adjustment, faulty thermostat, shorted heating element
Main causes: lack of power, no gas supply, thermostat limit switch tripped, bad element, bad thermostat, gas valve failure, bad thermocouple
Main causes: faulty pressure relief valve, water is overheating
Main causes: loose water pipe fittings, leaky drain valve, bad temperature-pressure relief valve, leaky heating element, cracked tank
Main causes: water supply needs chlorine treatment, anode rod too reactive

Repair guides for electric water heaters

How to replace an electric water heater heating element

If your water heater runs out of hot water quickly and one of the two heating elements has failed, replace the element following these step-by-step instructions.

Repair difficulty
Time required
 30 minutes or less
How to replace an electric water heater thermostat

If the water temperature fluctuates or you don't get enough hot water, follow these instructions to replace your water heater's thermostat.

Repair difficulty
Time required
 30 minutes or less
How to replace a water heater temperature and pressure (T&P) relief valve

Replace a broken temperature/pressure (T&P) relief valve on an electric water heater using these instructions.

Repair difficulty
Time required
 30 minutes or less

Articles and videos common to all water heaters

Use the advice and tips in these articles and videos to get the most out of your water heater.

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