How to Fix a Leaking Hot Water Heater Drain Valve

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Things You'll Need

  • Brass 3/4 inch ball valve

  • Plumbing wrench

  • Plumbing tape

  • Garden hose

Hot water heater drain valves are prone to leaking and breakage. A leaking hot water drain valve wastes energy, and can ruin anything in the immediate area. A slow leak can add up to hundreds of dollars in water damage repairs. Regular maintenance performed on a water heater will prolong the life of the unit.


If the water heater is leaking from the drain valve a replacement valve needs to be installed. Leakage from behind the valve may indicate the valve is loose.

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Hot Water Heater Maintenance Preparation

Step 1

Turn off the energy to the hot water heater. On an electric hot water heater flip the circuit breaker to the off position. On a gas hot water heater turn the pilot control lever to the pilot setting.


Step 2

Locate the cold water supply line to the hot water heater. Prevent the hot water tank from refilling by turning the water off.

Step 3

Connect a garden hose to the hot water heater drain valve and drain the water. Open the valve marked pressure release on the hot water heater. Turn on the closest water faucet to quicken the draining process.


Replacing the Drain Valve

Step 1

Use a plumbing wrench to take off the old water heater drain valve. Tighten the wrench onto the valve and turn in a counterclockwise motion releasing tension and backing the valve off of the valve nipple.


Step 2

Wrap the protruding valve nipple with plumbing tape. Wrap the tape tightly to reveal the threads underneath. Do not use crinkled or defective tape as this will cause leakage with the new valve.

Step 3

Replace the old water valve with a new 3/4 inch brass ball valve. Attach the threaded portion of the valve onto the valve nipple and turn clockwise until the ball valve is hand tight. Use the plumbing wrench to tighten the valve another turn


Step 4

Turn on the cold water supply to the hot water heater. Allow the tank to fill for ten minutes.

Step 5

Check the brass ball valve for leakage during the filling process. If any drips are noticed turn off the water supply and tighten the valve another turn. Continue this step until no leaks are present. Fill the tank completely and turn on the energy supply.


To fix a leak behind the drain valve wrap the valve nipple with plumbing tape.


Prevent burns by draining the water tank completely after it is turned off.



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