How to Prevent Plumbing Leaks Automatically

One homeowner, Joe, learned the hard way why passive detection isn’t enough. His alarm company called to alert him that his basement was flooding — and fortunately, he was home to control the damage. But as he explained to Richard Trethewey: “The problem is I travel a lot in my job. My wife and I take vacations, and the law of averages, this thing is gonna go when I’m not home. And by the time I call the security company, a neighbor comes, I’m gonna have a foot of water in the basement.” That experience led him to install an automatic water shutoff system that both detects leaks and closes the water supply — no human intervention required.

Pro Tip: Richard Trethewey, This Old House plumbing and heating expert, emphasizes the importance of automatic shutoff capability: a device that “senses the water leaking in the basement, but also shuts the water off” is far superior to a passive alarm system alone. As he notes, “full city water pressure coming in here can put some water into the basement” — and if you’re away from home, an alarm without automatic shutoff won’t prevent catastrophic damage.

Steps:

1. Shut off the water supply at the main shutoff valve.
2. Using the pipe cutter, cut into the pipe close to the water main.
3. Install the automatic valve and connect to it, using the appropriate fittings based on the style of your water supply piping.
4. Find a good place to place the receiver, close to the automatic shutoff. Connect the automatic shutoff to the receiver.
5. Program the sensors following the instructions included with the kit.

When installing a float-type sensor beneath a water heater, place the float inside a reservoir or drain pan positioned under the appliance. As demonstrated on a This Old House project, the float connects to the automatic valve via spade connections and a locking screw. Secure the sensor wiring with zip ties to keep everything tidy. To test, raise the float manually to simulate rising water — you should hear the valve close immediately, confirming the system is working.

Resources:

Richard demonstrated the RDT Reliance Wireless Plumbing Leak Protection System, which can be purchased through plumbing supply houses.

Expert assistance for this segment was provided by Morris Merchants.

Tools: