Whole Home Wireless Water Leak Detector and Emergency Water Shut Off System
Introduction: Whole Home Wireless Water Leak Detector and Emergency Water Shut Off System
I live in a second story condominium and I've always had a concern about a major water leak in my unit causing damage to my own home as well as my downstairs neighbor.
For years, I have placed a 9V water alarm in my water heater's pan, but such an alarm only does any good if I am home at the time.
In this Instructable, I will describe a wireless whole-home wireless water leak detector and shut off system.
The problem can roughly be divided into two parts:
* Electronically shutting of the water to your home
* Detecting the leaks and controlling the valve
For the first part, there major determining factor is whether you want to have a plumber install a motorized valve in your plumbing or whether you want a retrofit that requires no modifications to the home's existing plumbing.
The second part, the determining factor is whether you want a single unit which detects the leaks and shuts off the water at one location, or whether you want a whole home system that consists of a central control unit as well as one or more wireless sensor modules you can put throughout the house.
We will look at some of these options in turn. I will also share some of my failures and a few turn-key commercial solutions you may consider.
All design files for this project are available on GitHub.
Supplies
Option 1: User-Installable DIY Retro-fit Motorized Winch
* 12V 6 RPM Worm Gear Motor
* 12V DC Power Supply
* Fishing Line
* PVC Pipe
* 3D Printed Parts
Option 2 (Recommended): Plumber-Installed Motorized Ball-Valve:
* Taco Two-Way, Normally Open, 24VAC Motorized Zone Valve
* 24V AC Power Supply
Required: Water Leak Detector and Valve Shut-off Unit
* Adafruit HUZZAH32
* Adafruit Latching Mini Relay FeatherWing
* USB 5V Charger and USB cable (to power the ESP32)
Optional: Remote Water Leak Sensor Modules
* Adafruit HUZZAH32
* Lithium Ion Polymer Battery Ideal for Feathers
Step 1: First Option: Motorized Water Shut-Off Winch
Your home's plumbing likely already has a manual main water shutoff valve. One way to accomplish our goals is to use a motor to mechanically actuate the valve.
In an earlier Instructable, I had added a PVC extension lever to my water valve. This lever was meant to make it easier for me to reach the valve, but later I realized that the additional leverage would allow me to use a simple motorized winch and some fishing line to pull the valve closed. I made an end-cap for the lever with a small hole for a cotter pin. 459
I mounted everything such that when the valve was completely closed, the cotter pin would be pulled out by the tension on the line, allowing the motor to free-spin.
I searched for a "12V worm gear motor" on eBay and was able to purchase an inexpensive high-torque motor. I designed a pulley for the motor in OpenSCAD and a custom bracket that would allow me to clamp it to some pipes that ran parallel to the valve I wanted to shut off.
I then ran some fishing line from the pulley to the cotter pin. By connecting the motor to 12V, the pully will wind up the fishing line and pull the valve closed.
I chose to mount my winch to some parallel pipes, but it could be mounted any place that is appropriate for your situation.
Once installed, this valve can easily be controlled by a microcontroller such as the ESP32 with a relay board and a small plug-in 12V DC transformer.
Resources:
* Winch design files on GitHub
* Lever design files on GitHub
Step 2: A Failed Experiment: 3D Printed Clamp on Actuator
The goal for this step was to design a 3D printed part that can mount the motor directly to the to the pipe and close the tap manually. This would make it a relatively easy retrofit for existing plumbing and was meant to be a more elegant solution than my winch.
The challenge here is making the part strong enough to push the handle. I've build several prototypes and have made corrections to make the plastic parts as strong as they can be. While I resolved various failure modes, at last the hole for the D-shaped motor axle in the "pusher" part striped out and failed to transmit enough torque to turn the handle.
Even printing this part at 100% infill did not help. 459