In this video, This Old House plumbing and heating expert Richard Trethewey explains how to install a water heater shut-off valve.
Steps for Installing a Water Heater Shut-off Valve:
- Turn off the water to the water heater.
- Drain the water heater using an electric pump and garden hose.
- Shut off the gas, then disconnect the gas line from the water heater.
- Cut cold-water pipe leading to heater using a tubing cutter; repeat for hot-water pipe.
- Disconnect flue from top of heater.
- Lift heater, slide catch pan underneath, then set heater back down.
- Reconnect gas line, after applying pipe dope to threads.
- Screw the flue back onto heater.
- Reconnect the hot-water pipe by soldering on a repair coupling.
- Extend the overflow pipe with copper tubing down to catch pan.
- Solder a copper union onto a threaded adapter; thread the adapter onto the automatic shut-off valve.
- Solder a second threaded adapter onto the cold-water pipe.
- Use tubing cutter to cut away enough cold-water pipe to install the shut-off valve.
- Install shut-off valve to the cold-water pipe.
- Plug sensor into valve; place float in water pan.
- Turn the gas and water back on.
- Test the valve by turning on the heater and manually raising the float valve; the heater should automatically shut off.