A valve assembly comprising a housing having an inlet and space therefrom an outlet, means located in the housing for controlling the flow of fluid between the inlet and the outlet, said means including a main valve movable between a first relatively closed position and a second open position, said movement being controlled by a pilot valve assembly including a temperature sensitive member such that when the temperature in the fluid reaches a predetermined value the pilot valve is opened thereby allowing the main valve to move from said first to said second open position.
