The present application relates to a system (10) for sensing liquid level in a receptacle (16). The system comprises a capacitive sensing probe (12), for sensing a capacitance between the capacitive sensing probe (12) and an electrically conductive portion of the receptacle (16). The system also comprises a control circuit (15) connected to the capacitive sensing probe (12) for detecting a level of the liquid in the receptacle (16) based on said capacitance, a non-isolated AC power supply (11) arranged to power the control circuit (15), the non-isolated AC power supply (11) having an electrical connection between its input and its output, and at least one filter capacitor (C1, C2) connected in series between the capacitive sensing probe (12) and the control circuit (15).