Toilet Leak and Flood Prevention

Toilets account for about 30 percent of home water usage, and the EPA estimates that household water leaks add up to more than a trillion gallons a year, over 10,000 gallons per household. The economic and environmental costs of these preventable household leaks are substantial. Current low-cost leak-detection systems are unreliable and require human intervention, so the project sponsor challenged the team to design a better way to prevent water loss due to leaks. The team designed a low-cost, autonomous water shutoff device that integrates with common household toilets and runs continuously off a 9-volt battery. A latching two-way solenoid valve is installed at the wall angle stop and connected to a control box and power source on the side of the toilet tank. An adjustable timer is set to account for variations in fill rate and water pressure that cause flush time to vary. The control system is connected to a waterproof momentary pull switch installed in series with the flapper chain. The switch is triggered upon flushing which causes the valve to open for the duration of the tank fill time, after which the valve closes again, protecting against slow intermittent leaks, constant leaks and flooding.