A valve body defines an inlet, an outlet, a valving cavity disposed between the inlet and outlet and a valving surface between the inlet and the outlet. A valve is moveable to a position away from the valving surface for permitting flow from the inlet through the valving cavity to the outlet. The fluid flow rate sensor includes a probe having a detection module adapted to change condition in response to the presence of the flow of the fluid, a control module that is electrically connected to the probe that monitors the condition of the detection module over time (e.g., a temperature), determines a rate of change of that condition over time, and generates an output that is indicative of the rate of flow of the fluid, and a I/O module connected to the control module and communicating the output of the control module to another device or a user.