This is the only device on the market today that does not require the use of batteries, power, a sensor or even a pan (though still a good idea to have and also may be subject to code). This device was developed in order to protect your hot water heater from leaking onto your floor, or worse yet cause massive water damage onto multiple floors of your home or multi-level apartment complex. It is testable, reusable, and is reasonably priced to provide top of the line protection that the competition cannot offer.
The WHID is a device that works off of the pressure in your tank. If the pressure drops below a certain level, the WHID will activate. It is a patented device that is the only device that works solely in this manner.
See the videos below to see an illustrated version of how this unique device actually works and also how to install it.