Abstract: Systems and methods for fluid level detection are disclosed. In one embodiment, a sensor assembly includes at least one optical fiber adapted to at least one of transmit and receive an optical signal, and a moveable float member. The float member is adapted to move in a first direction as the fluid level increases and in a second direction as the fluid level decreases. The float member blocks the optical signal at a first value of the fluid level, and allows the optical signal to pass at a second value of the fluid level. The presence or absence of the optical signal is detected to determine the level of fluid.

Abstract: A device for controlling fluid flow for heating or cooling an associated system is provided. The present invention includes a housing having a flow control member that includes a bendable portion. The flow control member responds automatically to a pressure condition within the housing and opens or closes based on the direction and quantity of fluid flow and does not include any mechanical or electromechanical control components. The bendable portion may include, for example, a convoluted section. The flow control member is in an open position during a mode of operation of the associated system and is in a closed position in another mode of operation of the system.