Household flooding costs homeowners and insurance companies millions of dollars in damages every year in the United States alone. Bursting pipes or leaking or malfunctioning appliances, for instance, can cause such household flooding. The resultant flooding often causes damage to the surrounding environment as well as to the appliance itself. For example, flooding of laundry rooms is such a common occurrence that many housing codes now require washing machines to be positioned within catch basins. Thus, when the inevitable overflow occurs, it is hoped that the water will be contained within the catch basins and that the water will not flow into other regions of the laundry rooms.
However, unless the manually operated shut-off valves, which are typically positioned at the wall behind most washing machines, are closed, water can surge unrestricted through a burst supply hose or can spill from the tank of the malfunctioning washing machine. It is estimated that the unrestricted flow through the hoses or from the tanks can be on the order of 3 gallons per minute or 180 gallons an hour. Clearly, in an unmonitored situation, the flow of water will rapidly exceed the storage capacity of a catch basin and also can exceed the capacity of a drain positioned within the catch basin.
Toilets can be a source of flooding as well. Generally, toilets include both a float valve and a seal that stops the flow of water into the toilet. If a drain line of the toilet becomes plugged, or if the float valve or seal malfunctions, water can spill from within the toilet bowl or refill tank onto the floor. In addition, the water supply line to the toilet can become loosened or can fail. In such instances, water will be surging onto the bathroom floor until the manually operated valve, which is typically located behind the toilet, is shut off. Thus, large amounts of water can flood a bathroom if the condition remains unmonitored.
Water heaters can also be a source of flooding. If a tank of the water heater springs a leak or if a water line connected to the water heater breaks, water will surge into the dwelling until the supply valve to the water heater is shut off. With water heaters, however, it is also desirable to shut off the flow of electricity and heating fuel, such as oil or gas, to the water heater.
Many prior art appliance leak detector and shut-off systems include a water sensor, or leak detector pad, a controller, and a water supply valve. The leak detector pad is placed on the floor near an appliance to be monitored. Upon contacting water during flooding, the detector pad sends a signal to the control, which in turn causes the water supply valve to close to prevent further flooding.
What is still desired is a new and improved leak detector pad. Preferably the leak detector pad will be compact, ruggedized, waterproof, include no moving parts, be protected from dirt and corrosion, and be reusable after a flood. In addition, the leak detector pad will preferably be able to transmit an alarm signal a relatively long distance, such as 150 feet.