How to Fix a Water Heater that Leaks From the Drain Valve

A leaking drain valve can cost you money.

A water heater that leaks from the drain valve may wind up costing you money, not just in wasted water and energy bills, but in repairing expensive water damage. The best way to fix a water heater that leaks from the drain valve is to take apart and examine the drain valve for problems. Many water heaters use a drain valve similar to faucets found on the outside of homes.

Things You'll Need

• Garden hose
• Drain or bucket
• Screwdriver
• Adjustable wrench
• Washer
• Pipe thread compound

Instructions

Drain the Water Heater

1. Turn off the power or gas for the water heater.

2. Shut off the water supply for the heater. Look for the water supply valve mounted toward the top of the heater. Rotate the knob clockwise to shut off the water.

3. Connect a garden hose to the drain valve. Run the other end to a drain or, if possible, outside the house. You can also drain into a bucket, but be prepared to empty the bucket many times.

4. Open up the pressure-relief valve at the top of the tank. This usually is done by flipping the valve switch up.

5. Open the drain valve by turning the knob counterclockwise. Allow the heater to drain.

Fixing the Drain Valve

1. Loosen the screw holding the handle in place. Pull the handle up and off the stem.

2. Loosen the hexagonal nut located just underneath the handle. Pull the stem out of the faucet.

3. Check the stem for cracks or other damage. If damage is found, replace the entire stem assembly as this type of damage can't be fixed.

4. Turn the water heater valve stem upside down. Examine the rubber washer at the bottom. Replace the washer if it is damaged or worn out. To replace it, loosen the retention screw. Pull out the washer. Insert a new one into the valve. Secure it with the screw.

5. Dab the threads on the stem with pipe-thread compound. Insert the stem into the water heater drain valve. Tighten clockwise. Replace the handle and screw. Tighten the handle clockwise.

6. Restore the water supply for the heater. Close the pressure-relief valve. Restore the gas or electricity. Check the drain valve for leaks.

Tips & Warnings

• When replacing a stem, take the whole assembly to the store to help in getting the correct replacement.

References

• Chili Pepper Appliances: Flushing Your Hot Water Heater
• HammerZone.com; Replacing a Faucet Washer; Bruce W. Maki