Adding a Shut-Off Valve to a Water Heater

Tools:

water shut-off wrench
garden hose
slip-joint pliers
adjustable wrench
wire brush
shut-off valve
coupler
plumber's tape

1. Use the water-shut off wrench to turn the water off at the water meter connection. Also turn off the breaker supplying electricity to the water heater (or turn off gas if you have a gas water heater).

2. Attach a hose to the drain valve at the base of the heater and drain the water (figure A). Close the valve once the tank is empty.

3. Next, disconnect the cold water supply line on the top of the water heater. Firmly grasp the coupling with a pair of slip-joint pliers and use an adjustable wrench to remove the supply line (figure B). Wrap the jaws of the slip-joint pliers with tape to prevent scratching the coupling.

4. Use a wire brush and towel to clean any corrosion and/or old plumber's tape from the threads of the coupling (figure C). Wrap the couple with new plumber's tape.

5. Screw the new shut-off valve to the coupling (figure D). Be careful and make sure the threads match up correctly and are not cross-threaded.

6. Wrap plumber's tape around the new coupling and screw it into the top of the shut-off valve. Put more plumber's tape on the top of the coupling, then reconnect the cold water supply line (figure E). Again, use care to avoid cross-threading or stripping the threads. Tighten the connection with the pliers and adjustable wrench.

7. Turn the valve so that it's open, turn the water back on at the meter and fill up the tank and check for links. Finally, turn back on the power or gas.