A fluid level sensor assembly includes a first housing part having a fluid inlet and a fluid outlet and a fluid flow channel between the inlet and the outlet. The assembly also includes a sensor housing part formed on or integral with the first housing part and defining a sensing flow channel between a sensor end and a closed end, and has an opening from the sensing flow channel to the fluid flow channel of the first housing part. The assembly also includes level sensor components provided in the sensor flow channel at the sensor end, the level sensor components comprising: an actuator, and a switch component. The actuator and the switch component are arranged in the sensing flow channel such that when the pressure fluid in the fluid flow channel increases to increase the pressure in the sensing flow channel.