Abstract: A trigger mechanism is provided for a water heater fail safe valve assembly which automatically shuts off the flow of water to a water heater when leakage of water from the water heater is detected in an underlying catch tray. The trigger mechanism includes a vertical housing having a drive rod which is upwardly urged by a spring and holds a resilient valve closing component. A cam member holds the drive rod down, representing the open state of the valve. An accumulation of water in the catch tray causes the cam member to release the drive rod to an upper position which closes the valve.

Abstract: Apparatus for automatically shutting off the water supply to a leaking water heater includes a water collecting tray positionable beneath the heater, a valve mechanism attachable to the tray, a float mechanism, and an action arm interactive between the float mechanism and valve mechanism. When water collects in the tray, the float mechanism rises, causing the action arm to trigger the release of a spring-urged component of the valve mechanism to discontinue flow of water to the heater.

Abstract: An apparatus for automatically shutting off a water supply to a leaking water heater includes a water-collecting tray adapted to be positioned beneath a water heater, and a float mechanism removably attachable to the tray. The float mechanism has a float adapted to reside within the tray. An arm extends from the float, and terminates in a trigger extremity located outside the tray. The trigger extremity is positioned to push upwardly upon a holding block that secures an extremity of a coil spring. The holding block also secures a tether that extends to an operating lever of a water shut-off valve. When the float rises in the tank, it causes the trigger extremity to release the coil spring in tensioned state from the holding block. Such action pulls the operating lever downwardly, causing shut-off of the water supply.